Installation method of novel double-row steel sheet pile cofferdam structure

Abstract

The invention discloses an installation method of a novel double-row steel sheet pile cofferdam structure, which comprises the following steps of: installing I-shaped steel at the center of a set position of two rows of Larsen steel sheet pile groups, and respectively fixing two ends of the I-shaped steel in a pair of river levees; an outer Larsen steel sheet pile group is tightly installed on the side, away from water flow, of I-shaped steel, meanwhile, a plurality of first pile groups are arranged in an inner cavity of the side, away from the I-shaped steel, of the outer Larsen steel sheet pile group at intervals, and the bottom ends of the first pile groups are inserted into a foundation to be used for supporting the outer Larsen steel sheet pile group. An inner Larsen steel sheet pile group is installed on the side, close to water flow, of the I-shaped steel in an abutting mode, meanwhile, a plurality of second pile groups are arranged in an inner cavity of the Larsen steel sheet pile group between the inner Larsen steel sheet pile group and the I-shaped steel at intervals, and the bottom ends of the second pile groups are inserted into the foundation to be used for supporting the inner Larsen steel sheet pile group. The cofferdam structure installed through the installation method has good water flow impact resistance, anti-seepage performance and supporting stability.

Description

Technical Field

[0001] The present invention relates to the technical field of double-row steel sheet pile cofferdam construction, and more specifically, to an installation method of a novel double-row steel sheet pile cofferdam structure. Background Art

[0002] The structural types of cofferdam construction generally include earth-rock cofferdam and sheet pile cofferdam. The construction of a large earth-rock cofferdam is not ideal in terms of stability, foundation bearing capacity, anti-seepage and water-stopping, and the construction period is very long. The steel sheet pile cofferdam is small in size and has a small impact range. It can adopt a double-row sheet pile structure or a grid sheet pile structure. Compared with the grid steel sheet pile, the double-row steel sheet pile cofferdam structure has the advantages of strong stability, good water-stopping, and convenient recycling. Using a double-row steel sheet pile cofferdam as the structural type of cofferdam construction, the cofferdam structure formed by the splicing of Larsen steel sheet piles is set in the river channel to block the river water to form a closed space. At this time, the cofferdam structure in the upstream position will be continuously impacted by the river water for a long time due to the water-facing setting, which makes the splicing position of the Larsen steel sheet pile easily deformed and damaged due to the impact of the river water. In severe cases, it may cause the cofferdam structure to leak, seriously affecting the construction process. The deformation of the steel sheet pile is mainly due to its insufficient support points, and the long-term scouring of the river water causes it to deform. Therefore, it is of great significance to realize the installation of the connecting structure between the double-row steel sheet pile cofferdams and the installation of the double-row steel sheet pile cofferdams through a set installation method to enhance the stability of the steel sheet pile cofferdam structure. Summary of the invention

[0003] An object of the present invention is to provide a novel installation method of a double-row steel sheet pile cofferdam structure, wherein the installed cofferdam structure has good water flow impact resistance, anti-seepage performance and supporting stability.

[0004] In order to solve the above technical problems, the present invention provides a novel installation method of a double-row steel sheet pile cofferdam structure, wherein the cofferdam structure is arranged along the width direction of the river channel and covers between a pair of riverbanks, and comprises two rows of Larsen steel sheet pile groups arranged at intervals, which are arranged in a mirror image, wherein the Larsen steel sheet pile group far from the water flow is defined as an outer Larsen steel sheet pile group, and the Larsen steel sheet pile group close to the water flow is defined as an inner Larsen steel sheet pile group, and the installation method comprises the following steps: Step 1: Install an I-beam at the center of the set position of the two rows of Larsen steel sheet pile groups, and fix the two ends of the I-beam in a pair of riverbanks respectively; Step 2: Install an outer Larsen steel sheet pile group against the side of the I-beam away from the water flow, and at the same time, arrange multiple pile groups one at intervals in the inner cavity of the side of the outer Larsen steel sheet pile group away from the I-beam, and the bottom ends of the pile groups are inserted into the foundation to support the outer Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the inner concave part of the outer Larsen steel sheet pile group away from the I-beam; Step 3: Install an inner Larsen steel sheet pile group against the water flow side of the I-beam, and at the same time, arrange a plurality of pile groups 2 in the inner cavity of the Larsen steel sheet pile group between the inner Larsen steel sheet pile group and the I-beam, and insert the bottom ends of the pile groups into the foundation to support the inner Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the concave part of the inner Larsen steel sheet pile group facing the I-beam side; Among them, the I-beam connects two rows of Larsen steel sheet pile groups to form a whole, and multiple pile groups 1 and multiple pile groups 2 are arranged alternately.

[0005] Preferably, in step one, a plurality of vertical through openings are arranged at equal intervals on the top of the I-beam along the width of the river channel and located at the center of the I-beam. After both ends of the I-beam are fixed, a plurality of supporting piles are vertically inserted into the plurality of openings one by one, and the bottom ends of the supporting piles are inserted into the foundation.

[0006] Preferably, in step 2 and step 3, the pile group 1 and pile group 2 have the same structure and both include a pile seat and a pair of steel piles located in the pile seat, the rear side of the pile seat is in contact with the Larsen steel sheet pile, the front side is provided with a pair of arc grooves, a pair of steel columns are clamped in the pair of arc grooves, and the bottom ends of the pair of steel columns are vertically inserted into the foundation to fix the pile seat.

[0007] Preferably, in the step three, before installing the Nellasen steel sheet pile group, a plurality of support components are arranged on the web of the I-beam in a one-to-one correspondence with the plurality of pile groups 2. After the Nellasen steel sheet pile group is installed, the support components are in contact with and abut against the plurality of pile groups 2 in a one-to-one correspondence.

[0008] Preferably, the supporting assembly comprises a sliding seat with a T-shaped cross-section, a clamping seat and a driving mechanism arranged in the clamping seat, the sliding seat is slidably connected to the clamping seat, the driving mechanism comprises a rotating rod, a worm connected to the rotating rod as a whole, a worm wheel meshing with the worm, and a threaded rod connected to the center of the worm wheel, the rotating rod drives the rotation, one end of the threaded rod is fixedly connected to the center of the worm wheel, and the other end is threadedly connected to the center of the sliding seat, a threaded channel is arranged in the center of the sliding seat, the sliding seat contacts and tightly abuts against the pile group 2, and the clamping seat is connected to the I-beam; in the initial state, the sliding seat is driven to move close to the rotating rod side, and after the Nerarsen steel sheet pile group in step three is installed, multiple pile groups 2 are installed, and then the rotating rod is driven to rotate to push the sliding seat toward the pile group 2 until it is tightly abutted against the pile group 2.

[0009] Preferably, the clamping seat is fixedly connected to a connecting seat relative to the other side of the connecting sliding seat, and sliding blocks are arranged on the upper and lower sides thereof. A pair of slide grooves are relatively arranged on the pair of flange plates of the I-beam, and the upper and lower sliding blocks are slidably connected to the pair of slide grooves; while constructing step two, a plurality of support assemblies are slid from the two ends of a pair of slide grooves to between a pair of flange plates of the I-beam through the upper and lower sliding blocks, and are initially positioned to the set positions of the plurality of pile groups two; in step three, when installing the Nerarsen steel sheet pile group, the position of the support assembly can be adaptively adjusted by sliding the upper and lower sliding blocks according to the installation situation, so that the support assembly is located in the inner cavity of the steel sheet pile group corresponding to the pile group two.

[0010] Preferably, in step 2 and step 3, each row of Larsen steel sheet pile groups is formed by splicing multiple Larsen steel sheet piles, and adjacent Larsen steel sheet piles are connected to each other as a whole through the bending parts on both sides, and the bending parts on both sides of the Larsen steel sheet piles are provided with sealing strips. After the clamping, the sealing strips located at the bending parts are interference fit with each other, and each row of Larsen steel sheet pile groups can be installed as a whole after the overall assembly is completed, or can be installed by clamping in sequence.

[0011] The present invention has at least the following beneficial effects: 1. The installation method of the present invention facilitates the support of auxiliary steel sheet piles by arranging pile groups, I-beams and support components, thereby improving the supporting performance of Larsen steel sheet piles, thereby improving the performance of Larsen steel sheet piles in resisting water flow impact and the stability of steel sheet piles, and avoiding as much as possible the splicing positions of Larsen steel sheet piles from being easily deformed and damaged by the impact force of river water, which may cause water leakage and seepage in the cofferdam structure in severe cases.

[0012] 2. Sealing strips are provided at the bending parts on both sides of the Larsen steel sheet piles of the present invention. Adjacent Larsen steel sheet piles are clamped together through the bending parts. After clamping, the sealing strips located at the bending parts are in interference fit to seal the gaps between adjacent Larsen steel sheet piles, thereby achieving waterproof sealing.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the I-beam, the support assembly and the pile group in the present invention; Figure 3 It is a plan view of the support assembly of the present invention; Figure 4 It is a schematic diagram of the structure of pile group 1 and pile group 2 of the present invention; Figure 5It is a schematic structural diagram of the Larsen steel sheet pile group of the present invention.

[0015] Description of reference numerals: 1. Riverbank, 2. Larsen steel sheet pile, 3. I-beam, 4. Support pile, 5. Pile group one, 6. Pile group two, 7. Support assembly, 71. Sliding seat, 72. Threaded rod, 73. Snap-on seat, 74. Worm gear, 75. Worm, 76. Rotating rod, 77. Connecting seat, 78. Sliding block, 8. Pile seat, 9. Steel pile. DETAILED DESCRIPTION

[0016] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0017] It should be noted that, in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0018] like Figures 1 to 5 As shown, the present invention provides a novel installation method of a double-row steel sheet pile cofferdam structure, wherein the cofferdam structure is arranged along the width direction of the river channel and covers between a pair of riverbanks 1, and comprises two groups of Larsen steel sheet piles 2 arranged at intervals, which are arranged in a mirror image, and the Larsen steel sheet pile group far from the water flow is defined as an outer Larsen steel sheet pile group, and the Larsen steel sheet pile group close to the water flow is defined as an inner Larsen steel sheet pile group. The installation method comprises the following steps: Step 1: Install an I-beam at the center of the set position of the two rows of Larsen steel sheet pile groups, and fix the two ends of the I-beam in a pair of riverbanks respectively; Step 2: Install an outer Larsen steel sheet pile group against the side of the I-beam away from the water flow, and at the same time, arrange multiple pile groups one at intervals in the inner cavity of the side of the outer Larsen steel sheet pile group away from the I-beam, and the bottom ends of the pile groups are inserted into the foundation to support the outer Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the inner concave part of the outer Larsen steel sheet pile group away from the I-beam; Step 3: Install an inner Larsen steel sheet pile group against the water flow side of the I-beam, and at the same time, arrange a plurality of pile groups 2 in the inner cavity of the Larsen steel sheet pile group between the inner Larsen steel sheet pile group and the I-beam, and insert the bottom ends of the pile groups into the foundation to support the inner Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the concave part of the inner Larsen steel sheet pile group facing the I-beam side; Among them, the I-beam connects two rows of Larsen steel sheet pile groups to form a whole, and multiple pile groups 1 and multiple pile groups 2 are arranged alternately.

[0019] An I-beam 3 is arranged between the two rows of Larsen steel sheet piles 2 groups, which connects the two rows of Larsen steel sheet piles 2 groups to form a whole, and the two ends of the I-beam 3 are respectively fixed in a pair of riverbanks 1, the two groups of Larsen steel sheet piles close to the water flow are the inner two groups of Larsen steel sheet piles, and the two groups of Larsen steel sheet piles away from the water flow are the outer two groups of Larsen steel sheet piles, and the inner cavity intervals of the two groups of Larsen steel sheet piles between the inner two groups of Larsen steel sheet piles and the I-beam 3 are provided with a plurality of pile groups 2 6, and the inner cavity intervals of the two groups of outer Larsen steel sheet piles on the side away from the I-beam 3 are provided with a plurality of pile groups 1 5, the pile groups 1 5 and the pile groups 2 6 are staggered with each other and the bottom ends are inserted into the foundation for supporting the two groups of Larsen steel sheet piles.

[0020] The double-layer cofferdam structure is composed of two rows of Larsen steel sheet piles arranged along the width of the river channel. Each row of Larsen steel sheet piles is formed by splicing multiple Larsen steel sheet piles, and the two rows of Larsen steel sheet piles are mirror images of each other. An I-beam 3 is arranged between the two rows of Larsen steel sheet piles. The two rows of Larsen steel sheet piles are connected to form a whole through the I-beam 3, so that the two rows of Larsen steel sheet piles can support each other, which greatly improves the impact resistance of the double-layer cofferdam structure composed of the Larsen steel sheet piles and increases the stability of the cofferdam structure.

[0021] Pipe piles are arranged in the inner cavity of each Larsen steel sheet pile 2, and the pipe piles are divided into a pile group 2 6 located between two rows of Larsen steel sheet piles 2 and a pile group 1 5 located on the side away from the two rows of Larsen steel sheet piles 2. The two groups of Larsen steel sheet piles close to the water flow are the inner Larsen steel sheet piles group 2, and the two groups of Larsen steel sheet piles away from the water flow are the outer Larsen steel sheet piles group 2. A plurality of pile groups 2 6 are arranged at intervals in the inner cavity between the two groups of inner Larsen steel sheet piles and the I-beam 3. A plurality of pile groups 1 5 are arranged at intervals on the side of the two groups of outer Larsen steel sheet piles away from the I-beam 3. The pile groups 1 5 and the pile groups 2 6 are arranged alternately. Each Larsen steel sheet pile 2 is provided with a pile group 1 5 or a pile group 2 6. The pile groups 2 6 and the pile groups 1 5 are tightly fitted with the corresponding Larsen steel sheet piles 2 to support the Larsen steel sheet piles 2 and improve the performance of the Larsen steel sheet piles 2 in resisting water flow impact. The support of the connection between the Larsen steel sheet piles 2 by the pile groups 2 6 and the pile groups 1 5 can avoid deformation of the Larsen steel sheet piles 2 in the water-facing position due to impact when the river water impacts.

[0022] In another technical solution, Figure 2 As shown, in the step one, a plurality of vertical through openings are arranged at equal intervals along the width direction of the river channel on the top of the I-beam, which are located at the center of the I-beam. After both ends of the I-beam are fixed, a plurality of supporting piles are vertically inserted into the plurality of openings one by one, and the bottom ends of the supporting piles are inserted into the foundation.

[0023] The top outer wall of the I-beam 3 is provided with a plurality of equally spaced rectangular openings, in which support piles 4 are inserted. Both ends of the I-beam 3 are fixed in the river bank 1, and the bottom ends of the support piles 4 are inserted in the foundation, thereby improving the stability of the I-beam 3.

[0024] In another technical solution, Figure 4 As shown, in step 2 and step 3, the pile group 1 and pile group 2 have the same structure and both include a pile seat and a pair of steel piles located in the pile seat, the rear side of the pile seat is fitted with the Larsen steel sheet pile, and the front side is provided with a pair of arc grooves, a pair of steel columns are clamped in the pair of arc grooves, and the bottom ends of the pair of steel columns are vertically inserted into the foundation to fix the pile seat, thereby fixing the entire pile group 1 5 or pile group 2 6.

[0025] The pile group 1 5 and the pile group 2 6 have the same structure and are mainly composed of two steel piles 9 and a pile seat 8. One side of the pile seat 8 is fitted with the Larsen steel sheet pile 2, and the other side is provided with two arc grooves. The two steel piles 9 are clamped in the arc grooves to facilitate the fixing of the pile seat 8 on the steel pile 9. The bottom ends of the pile group 2 6 and the pile group 1 5 are inserted into the foundation to protect the connection of the Larsen steel sheet pile 2. At the same time, multiple pile groups 1 5 and pile groups 2 6 can effectively support the Larsen steel sheet pile 2 in conjunction with the I-beam 3 and the support assembly 7, greatly improving the impact resistance of the splicing position of the Larsen steel sheet pile 2.

[0026] In another technical solution, Figure 2 As shown, in the step three, before installing the Nellasen steel sheet pile group, a plurality of support components are arranged one-to-one at corresponding positions of the plurality of pile groups 2 on the web of the I-beam. After the Nellasen steel sheet pile group is installed, the support components are in contact with and abut against the plurality of pile groups 2 one-to-one.

[0027] A plurality of support components 7 are arranged on the I-beam 3, and the support components 7 on the I-beam 3 can assist the inner Larsen steel sheet piles 2 in supporting. The I-beam 3 directly contacts the concave part of the inner Larsen steel sheet piles 2, and the support components 7 mainly contact the convex part of the inner Larsen steel sheet piles 2, so as to effectively support the Larsen steel sheet piles 2. The cooperation among the I-beam 3, the support components 7, the pile group 1 5 and the pile group 2 6 improves the integrity of the two Larsen steel sheet piles 2, and can effectively support the Larsen steel sheet piles 2, so as to effectively avoid the problem of local deformation of the Larsen steel sheet piles 2.

[0028] In another technical solution, Figure 3As shown, the support assembly 7 includes a sliding seat 71 with a T-shaped cross section, a clamping seat 73 and a driving mechanism arranged in the clamping seat, the sliding seat is slidably connected to the clamping seat, the driving mechanism includes a rotating rod 76, a worm 75 connected to the rotating rod as a whole, a worm wheel 74 meshing with the worm, and a threaded rod 72 connected to the center of the worm wheel, the rotating rod is driven to rotate, one end of the threaded rod is fixedly connected to the center of the worm wheel, and the other end is threadedly connected to the center of the sliding seat, a threaded channel is arranged in the center of the sliding seat, the sliding seat contacts and tightly abuts against the pile group 2 6, and the clamping seat is connected to the I-beam 3. In the initial state, the sliding seat is driven to move close to the rotating rod side, after the Nerarsen steel sheet pile group in step 3 is installed, multiple pile groups 2 are installed, and then the rotating rod is driven to rotate to push the sliding seat toward the pile group 2 until it is tightly abutted against the pile group 2.

[0029] The said clamping seat is fixedly connected with a connecting seat 77 relative to the other side of the connecting sliding seat, and the upper and lower sides thereof are provided with sliding blocks 78. A pair of slide grooves are relatively provided on a pair of flange plates of the said I-beam 3, and the upper and lower sliding blocks are slidably connected to the pair of slide grooves. While constructing step 2, a plurality of support components are slid from the two ends of a pair of slide grooves to between a pair of flange plates of the I-beam through the upper and lower sliding blocks, and are initially positioned to the set positions of a plurality of said pile groups 2; in step 3, when installing the inner Larsen steel sheet pile group, according to the installation situation, the position of the support component can be adaptively adjusted by sliding the upper and lower sliding blocks, so that the support component is located in the inner cavity of the steel sheet pile group corresponding to the pile group 2.

[0030] The supporting assembly 7 mainly comprises a clamping seat and a sliding seat. The cross section of the sliding seat is a T-shaped structure, and one end of the sliding seat is in contact with the pile seat 8. A driving mechanism is arranged in the clamping seat, and the driving mechanism can directly adjust the position of the sliding seat, so as to facilitate effective support of the Larsen steel sheet pile 2. The driving mechanism comprises a threaded rod rotatably installed in the clamping seat, the sliding seat is screwed on the outer wall of the threaded rod, one end of the threaded rod is fixedly connected with a worm gear, and the inner wall of the clamping seat is rotatably connected with a worm, and the worm gear and the worm gear are meshed. The inner wall of the clamping seat is rotatably installed with a rotating rod that passes through the clamping seat, and one end of the rotating rod is connected with the worm gear. At the same time, the supporting assembly 7 is relatively independent and can adjust the position of the sliding seat according to actual conditions. A clamping mechanism is arranged on the clamping seat. The setting of the clamping mechanism is convenient for clamping the supporting assembly 7 in the groove of the I-beam 3, so as to facilitate the disassembly of the supporting assembly 7 at a later stage. The clamping mechanism comprises a connecting seat, and sliding blocks are installed on the outer walls of both sides of the connecting seat, and the inner walls of both sides of the I-beam 3 are provided with sliding grooves matching the sliding blocks. When installing, the support assembly 7 is slid from the end of the slide slot to between the I-beams 3; when disassembling, the support assembly 7 is slid from between the I-beams 3 to the end of the slide slot. The rotation of the rotating rod can be driven by a micro motor or other feasible driving mechanism.

[0031] The adjustable support assembly 7 can adjust the support effect of the support assembly 7 according to the actual situation, effectively avoiding the problem that the splicing position of the Larsen steel plate is easily deformed and damaged due to the impact force of the river water, which may cause leakage of the cofferdam structure in severe cases and seriously affect the construction progress.

[0032] In another technical solution, Figure 5 As shown, in step 2 and step 3, each row of Larsen steel sheet piles 2 is formed by splicing multiple Larsen steel sheet piles 2, and adjacent Larsen steel sheet piles 2 are connected to each other as a whole through the bending parts on both sides. The bending parts on both sides of the Larsen steel sheet piles 2 are provided with sealing strips. After the clamping, the sealing strips located at the bending parts are interference fit. Each row of Larsen steel sheet piles can be installed as a whole after the overall assembly is completed, or can be installed by clamping in sequence.

[0033] The connecting structure is a connecting part formed by bending both sides of the Larsen steel sheet pile 2 for mutual clamping. Adjacent Larsen steel sheet piles 2 are clamped to each other through the connecting part. The clamping connection method is convenient for the installation and disassembly of the Larsen steel sheet piles 2, which greatly improves the construction efficiency and facilitates the subsequent recycling and reuse of the Larsen steel sheet piles 2, greatly saving resources.

[0034] The waterproof structure includes a sealing strip arranged at the connection position of the Larsen steel sheet pile 2. When adjacent Larsen steel sheet piles 2 are clamped together through the bending portion, the sealing strips located at the bending portion are interference fit between each other, which greatly improves the sealing performance of the connection position of the Larsen steel sheet pile 2 and minimizes the leakage of river water through the small gap at the connection between two adjacent Larsen steel plates.

[0035] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily implemented, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A novel installation method of a double-row steel sheet pile cofferdam structure, characterized in that: The cofferdam structure is arranged along the width of the river channel and covers between a pair of riverbanks, and includes two rows of Larsen steel sheet pile groups arranged at intervals, which are arranged in a mirror image. The Larsen steel sheet pile group far from the water flow is defined as the outer Larsen steel sheet pile group, and the Larsen steel sheet pile group close to the water flow is defined as the inner Larsen steel sheet pile group. The installation method includes the following steps: Step 1: Install an I-beam at the center of the set position of the two rows of Larsen steel sheet pile groups, and fix the two ends of the I-beam in a pair of riverbanks respectively; Step 2: Install an outer Larsen steel sheet pile group against the side of the I-beam away from the water flow, and at the same time, arrange multiple pile groups one at intervals in the inner cavity of the side of the outer Larsen steel sheet pile group away from the I-beam, and the bottom ends of the pile groups are inserted into the foundation to support the outer Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the inner concave part of the outer Larsen steel sheet pile group away from the I-beam; Step 3: Install an inner Larsen steel sheet pile group against the water flow side of the I-beam, and at the same time, arrange a plurality of pile groups 2 in the inner cavity of the Larsen steel sheet pile group between the inner Larsen steel sheet pile group and the I-beam, and insert the bottom ends of the pile groups into the foundation to support the inner Larsen steel sheet pile group; the flange plate of the I-beam contacts and abuts against the concave part of the inner Larsen steel sheet pile group facing the I-beam side; Among them, the I-beam connects two rows of Larsen steel sheet pile groups to form a whole, and multiple pile groups 1 and multiple pile groups 2 are arranged alternately.

2. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 1 is characterized in that: In the step one, a plurality of vertical through openings are arranged at equal intervals on the top of the I-beam along the width of the river channel, and are located at the center of the I-beam. After both ends of the I-beam are fixed, a plurality of supporting piles are vertically inserted into the plurality of openings one by one, and the bottom ends of the supporting piles are inserted into the foundation.

3. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 1 is characterized in that: In step 2 and step 3, pile group 1 and pile group 2 have the same structure and both include a pile seat and a pair of steel piles located in the pile seat, the rear side of the pile seat is in contact with the Larsen steel sheet pile, and the front side is provided with a pair of arc grooves, a pair of steel columns are clamped in the pair of arc grooves, and the bottom ends of the pair of steel columns are vertically inserted into the foundation to fix the pile seat.

4. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 3 is characterized in that: In the step three, before installing the Nellasen steel sheet pile group, a plurality of support components are arranged one-to-one at corresponding positions of the plurality of pile groups 2 on the web of the I-beam. After the Nellasen steel sheet pile group is installed, the support components are in contact with and abut against the plurality of pile groups 2 one-to-one.

5. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 4 is characterized in that: The supporting assembly comprises a sliding seat with a T-shaped cross-section, a clamping seat and a driving mechanism arranged in the clamping seat, the sliding seat is slidably connected to the clamping seat, and the driving mechanism comprises a rotating rod, a worm connected to the rotating rod as a whole, a worm wheel meshing with the worm, and a threaded rod connected to the center of the worm wheel, the rotating rod drives to rotate, one end of the threaded rod is fixedly connected to the center of the worm wheel, and the other end is threadedly connected to the center of the sliding seat, a threaded channel is arranged in the center of the sliding seat, the sliding seat contacts and tightly abuts against the pile group 2, and the clamping seat is connected to the I-beam; in the initial state, the sliding seat is driven to move close to the rotating rod side, and after the Nerarsen steel sheet pile group in step three is installed, multiple pile groups 2 are installed, and then the rotating rod is driven to rotate to push the sliding seat toward the pile group 2 until it is tightly abutted against the pile group 2.

6. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 5 is characterized in that: The clamping seat is fixedly connected to a connecting seat relative to the other side of the connecting sliding seat, and sliding blocks are arranged on the upper and lower sides thereof. A pair of slide grooves are relatively arranged on a pair of flange plates of the I-beam, and the upper and lower sliding blocks are slidably connected to the pair of slide grooves; while constructing step 2, a plurality of support assemblies are slid from the two ends of a pair of slide grooves to between a pair of flange plates of the I-beam through the upper and lower sliding blocks, and are initially positioned to the set positions of the plurality of pile groups two; in step 3, when installing the Nerarsen steel sheet pile group, according to the installation situation, the position of the support assembly can be adaptively adjusted by sliding the upper and lower sliding blocks, so that the support assembly is located in the inner cavity of the steel sheet pile group corresponding to the pile group two.

7. The installation method of the novel double-row steel sheet pile cofferdam structure according to claim 1 is characterized in that: In step 2 and step 3, each row of Larsen steel sheet pile groups is formed by splicing multiple Larsen steel sheet piles, and adjacent Larsen steel sheet piles are connected to each other as a whole through the bending parts on both sides. The bending parts on both sides of the Larsen steel sheet piles are provided with sealing strips. After the clamping, the sealing strips located at the bending parts are in interference fit. Each row of Larsen steel sheet pile groups can be installed as a whole after the overall assembly is completed, or can be installed by clamping in sequence.

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