Coastal Bridge Deep Foundation Pit Protection Structure and Construction Method

Abstract

The present invention discloses a deep foundation pit protection structure for coastal bridges, comprising: a first support body, which is formed by concrete pouring, and the first support body is supported on the side wall of the deep foundation pit at an angle of 30 degrees with the vertical direction; a receiving platform, which is formed by concrete pouring, and the receiving platform is connected to the lower end of the first support body; a second support body, which is formed by concrete pouring, and the second support body is connected to the lower end of the receiving platform, and the second support body is arranged at an angle of 150 degrees with the horizontal plane of the receiving platform; wherein, a water guiding structure is arranged on the receiving platform, and a plurality of mounting seats are arranged at intervals on the top of the first support body, one end of a plurality of diversion grooves is arranged on the mounting seats, and the other end extends to the water guiding structure. The present invention can, in view of the particularity of coastal geology, avoid the problem of water seeping into the side wall of the deep foundation pit during the excavation of the deep foundation pit, resulting in the overturning of the protection structure.

Description

Technical Field

[0001] The present invention relates to the technical field of coastal bridge construction. More specifically, the present invention relates to a protection structure and construction method for deep foundation pits of coastal bridges. Background Art

[0002] The construction areas of coastal bridges are mostly clay, sand, sandy clay, gravelly clay, etc., and there may also be "V-shaped" and "U-shaped" valleys along the line, and the construction site is narrow. In existing deep foundation pit construction, a support structure is often used to support the side walls of the deep foundation pit to ensure the safety of deep foundation pit construction and the surrounding buildings during construction. However, the deep foundation pit support structure for coastal bridge projects lacks a water seepage and drainage structure. It is easy to cause the soil at the lower end of the side wall of the foundation pit to slide during construction, resulting in the overall overturning of the support structure, and further affecting the safety and stability of the support structure. For example, the application number is 202323595242.3, and the name is a deep foundation pit support structure, which includes a plurality of steel pipe columns vertically fixed at the bottom of the deep foundation pit and arranged at equal intervals along the length direction of the deep foundation pit. A retaining plate is fixedly arranged between the steel pipe column and the slope of the deep foundation pit, and backfill soil is fixedly arranged between the retaining plate and the slope of the deep foundation pit. It realizes the support function through the combination of a plurality of steel pipe columns, retaining plates and backfill soil. However, for the deep foundation pit protection of coastal bridges, problems such as water seepage and overturning of the support structure are likely to occur. Summary of the Invention

[0003] An object of the present invention is to solve at least the above problems and provide at least the advantages described later.

[0004] Another object of the present invention is to provide a protection structure for deep foundation pits of coastal bridges, which can provide effective protection during the excavation of deep foundation pits.

[0005] To achieve these and other advantages in accordance with the present invention, there is provided a protection structure for deep foundation pits of coastal bridges, comprising:

[0006] A first support body, which is formed by concrete pouring, and the first support body is supported on the side wall of the deep foundation pit at an angle of 30 degrees to the vertical direction;

[0007] A receiving platform, which is formed by concrete pouring, and the receiving platform is connected to the lower end of the first support body;

[0008] A second support body, which is formed by concrete pouring, the second support body is connected to the lower end of the receiving platform, and the second support body is arranged at an angle of 150 degrees to the horizontal plane of the receiving platform;

[0009] Among them, the first support body is provided with a first diversion groove and a second diversion groove extending from top to bottom. The first diversion groove and the second diversion groove are spiral. A sediment layer is arranged between the first diversion groove and the second diversion groove. A water guiding structure is arranged on the receiving platform. The water guiding structure includes a first filtering layer, a second filtering layer and a water guiding layer. The water guiding layer is located below the first filtering layer and the second filtering layer. The first filtering layer is communicated with the first diversion groove. The second filtering layer is communicated with the second diversion groove. A first sediment filter screen is arranged on the first filtering layer. A second sediment filter screen is arranged on the second filtering layer. The water guiding layer is communicated with a water collecting pool arranged around the deep foundation pit.

[0010] Preferably, the coastal bridge deep foundation pit protection structure further includes:

[0011] A plurality of support columns, which are vertically and spacedly arranged below the receiving platform;

[0012] A plurality of diversion columns, which are horizontally arranged on both sides of the support columns. One end of the diversion column is communicated with the connected support column, and the other end extends to the water collecting pool;

[0013] Among them, the top of the support column close to the first support body is connected to the first support body through 2 first reinforcing ribs. The top of the support column close to the second support body is connected to the second support body through 2 second reinforcing ribs. A sand passing structure is arranged at the lower end of each support column. A plurality of sand screening holes are arranged on the sand passing structure.

[0014] Preferably, the coastal bridge deep foundation pit protection structure further includes:

[0015] A plurality of siphons, which are correspondingly arranged in a plurality of support columns. One siphon is arranged in each support column. The siphon has an "L" - shaped structure. One end of the siphon extends to the bottom of the support column and is located above the sand passing structure, and the other end extends to the diversion column. The distance between one end of the siphon and the sand passing structure is 1 - 3 cm.

[0016] Preferably, the coastal bridge deep foundation pit protection structure further includes:

[0017] A first water retaining structure, which is arranged around the first filtering layer on its three peripheries not connected to the first diversion groove;

[0018] A second water retaining structure, which is arranged around the second filtering layer on its three peripheries not connected to the second diversion groove.

[0019] Preferably, the coastal bridge deep foundation pit protection structure further includes:

[0020] A plurality of first grouting pipes are arranged at intervals on the first support body. One end of any first grouting pipe protrudes from the first support body, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the first support body.

[0021] A plurality of second grouting pipes are arranged at intervals on the second support body. One end of any second grouting pipe protrudes from the second support body, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the second support body.

[0022] Preferably, on both sides of any first reinforcing rib, first hinge rings are respectively arranged. The first hinge rings are hinged to the top ends of the first support body and the support columns. On both sides of any second reinforcing rib, second hinge rings are respectively arranged. The second hinge rings are hinged to the top ends of the second support body and the support columns.

[0023] The present invention is further realized by a construction method of the coastal bridge deep foundation pit protection structure. The construction method of the coastal bridge deep foundation pit protection structure includes the following steps:

[0024] Step 1: Use concrete pouring to form the first support body and the second support body. Among them, a plurality of first grouting pipes are arranged on the first support body, and a plurality of second grouting pipes are arranged on the second support body. On the first support body, a spiral-shaped first diversion groove and a second diversion groove are formed by concrete pouring through a support formwork. A sedimentation layer is erected between the first diversion groove and the second diversion groove.

[0025] Step 2: Use concrete pouring to form the water guide layer of the receiving platform. The water guide layer is a trough-shaped structure. One end of the water guide layer away from the water collecting pool is a concrete column structure supporting a first filter layer thereon. The end close to the water collecting pool is supported by steel bars for a second filter layer. A first sediment filter screen is arranged on the first filter layer, and a second sediment filter screen is arranged on the second filter layer. A first water retaining structure is arranged on three peripheries of the first filter layer, and a second water retaining structure is arranged on three peripheries of the second filter layer.

[0026] Step 3: Measure and set out the lines, excavate a protection area on the side wall of the deep foundation pit, and lay a bottom plate at the bottom of the protection area.

[0027] Step 4: Set a sand passing structure at the lower end of each support column, connect a plurality of diversion columns with a plurality of support columns to form a lower diversion structure, and arrange the diversion structure on the bottom plate. Arrange a receiving platform on the diversion structure, and connect the first support body and the second support body to the receiving platform respectively according to the set angles. Among them, the first support body and the receiving platform, and the receiving platform and the second support body are connected by a tenon and mortise joint method. Lay a siphon from the end of the diversion column to the end of the support column until one end of the siphon is 1 - 3 cm away from the sand passing structure.

[0028] Step 5: Inject grout into the gaps between the deep foundation pit and the first support, the receiving platform, and the second support through multiple first grouting pipes and multiple second grouting pipes;

[0029] Step 6: Demolish the bottom plate after the grout solidifies.

[0030] The present invention has at least the following beneficial effects:

[0031] 1. In view of the particularity of the coastal geology, the deep foundation pit protection structure is designed to have an overall slope-like structure, which facilitates the rainwater and other construction-generated water to flow into the water guiding structure of the receiving platform along the first diversion groove and the second diversion groove designed on the first support. Both ends of the water guiding structure are connected to the sump of the deep foundation pit, and then flow into the sump, avoiding the infiltration of water into the side wall of the deep foundation pit and causing the problem of the overturning of the protection structure.

[0032] 2. The first diversion groove and the second diversion groove are set in a spiral shape. When the rain is heavy, the energy of the scouring water with a large scouring energy is dissipated to slow down the water flow speed and reduce its scouring damage ability to the receiving platform. By setting a sedimentation layer between the first diversion groove and the second diversion groove, the sand and stones scoured by the rainwater are initially deposited.

[0033] 3. By arranging a plurality of support columns and diversion column structures under the receiving platform, one end of the diversion column extends to the sump, avoiding the infiltration of groundwater generated during the construction of the deep foundation pit from bottom to top into the deep foundation pit protection structure and causing the problem of the collapse and overturning of the deep foundation pit protection structure.

[0034] 4. By setting a sand passing structure at the lower end of each support column, the filtration of sand and stones in the groundwater is realized, avoiding the suction into the support column and the diversion column and causing pipeline blockage.

[0035] 5. By arranging siphons in the support columns and the diversion columns, the groundwater generated during the construction of the deep foundation pit is quickly sucked into the sump through the siphon principle, avoiding the long-term immersion of the bottom of the deep foundation pit and causing the collapse of the protection structure.

[0036] 6. A first water retaining structure is arranged around three sides of the first filter layer, and a second water retaining structure is arranged around three sides of the second filter layer, avoiding the water flow overflowing from the water guiding structure and flowing into the deep foundation pit.

[0037] Other advantages, objectives and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the deep foundation pit protection structure of the coastal bridge in one technical solution of the present invention;

[0039] Figure 2Schematic diagram of the structures of the first diversion channel and the second diversion channel in another technical solution of the present invention;

[0040] Figure 3 Schematic diagram of the water guiding structure in another technical solution of the present invention;

[0041] Figure 4 Schematic diagram of the structures of a single support column and a diversion column in another technical solution of the present invention;

[0042] Figure 5 Arrangement schematic diagram of multiple support columns and diversion columns in another technical solution of the present invention;

[0043] Reference numerals: 1: first support body, 100: first diversion channel, 110: second diversion channel, 120: sediment layer, 2: receiving platform, 200: first filter layer, 210: second filter layer, 220: water guiding layer, 230: first sediment filter screen, 240: second sediment filter screen, 3: second support body, 4: support column, 400: sand passing structure, 410: sand screening hole, 5: diversion column, 6: siphon, 7: first water retaining structure, 8: second water retaining structure, 9: first reinforcing rib, 10: second reinforcing rib, 11: first grouting pipe, 12: second grouting pipe. Detailed implementation manners

[0044] The following further elaborates on the present invention with reference to the accompanying drawings, so that those skilled in the art can implement it according to the description in the specification.

[0045] It should be understood that terms such as "having", "comprising", and "including" as used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0046] As Figures 1 to 3 shown, the present invention provides a coastal bridge deep foundation pit protection structure, including:

[0047] A first support body 1, which is formed by concrete pouring, and the first support body 1 is supported on the side wall of the deep foundation pit at an angle of 30 degrees to the vertical direction;

[0048] A receiving platform 2, which is formed by concrete pouring, and the receiving platform 2 is connected to the lower end of the first support body 1;

[0049] A second support body 3, which is formed by concrete pouring, and the second support body 3 is connected to the lower end of the receiving platform 2, and the second support body 3 is arranged at an angle of 150 degrees to the horizontal plane of the receiving platform 2;

[0050] Among them, the first support 1 is provided with a first diversion groove 100 and a second diversion groove 110 extending from top to bottom. The first diversion groove 100 and the second diversion groove 110 are spiral. A sedimentation layer 120 is arranged between the first diversion groove 100 and the second diversion groove 110. A water guiding structure is arranged on the receiving platform 2. The water guiding structure includes a first filter layer 200, a second filter layer 210 and a water guiding layer 220. The water guiding layer 220 is located below the first filter layer 200 and the second filter layer 210. The first filter layer 200 is communicated with the first diversion groove 100. The second filter layer 210 is communicated with the second diversion groove 110. A first sediment filter screen 230 is arranged on the first filter layer 200. A second sediment filter screen 240 is arranged on the second filter layer 210. The water guiding layer is communicated with a catch basin arranged around the deep foundation pit.

[0051] In the above technical solution, the side wall of the first support 1 close to the deep foundation pit is supported on the side wall of the deep foundation pit at an angle of 30 degrees with the vertical direction. The top end of the first support 1 and the side wall of the deep foundation pit are connected by means of concrete slab tenon joints. The lower end of the first support is connected to one end of the receiving platform by means of tenon joints. The other end of the receiving platform is connected to the upper end of the second support 3 by means of tenon joints. After the three are connected, they form an integral structure and are supported above the cast-in-place support structure as a protective structure for the side wall of the deep foundation pit. A first diversion channel 100 and a second diversion channel 110 are provided extending from the top to the bottom of the first support 1. The first diversion channel 100 and the second diversion channel 110 are arranged in a spiral shape. When the rain is heavy, the water flow with a large scouring energy is dissipated to slow down the water flow speed and reduce its scouring damage ability to the receiving platform. By arranging a sedimentation layer 120 between the first diversion channel 100 and the second diversion channel 110, the sand and stones scoured by the rainwater are initially deposited. The first diversion channel 100 and the second diversion channel 110 are in a flat structure at the location where the sedimentation layer 120 is arranged, and the sedimentation layer 120 is fixed by drilling holes in the first diversion channel 100 and the second diversion channel 110. A first filter layer 200 is arranged on the receiving platform corresponding to the position of the first diversion channel 100 to filter and deposit the sediment in the rainwater flowing down from the first diversion channel 100. A second filter layer 210 is arranged on the receiving platform corresponding to the position of the second diversion channel 110 to filter and deposit the sediment in the rainwater flowing down from the second diversion channel 110. One end of the water diversion structure is arranged corresponding to the first diversion channel 100, and the other end extends above the catch basins arranged around the deep foundation pit. In view of the particularity of the coastal geology, the deep foundation pit protection structure is designed to have an overall slope structure, which is convenient for the rainwater and other construction-generated water to flow into the water diversion structure of the receiving platform 2 along the first diversion channel 100 and the second diversion channel 110 designed on the first support. One end of the water diversion structure is communicated with the catch basin of the deep foundation pit and then flows into the catch basin, avoiding the infiltration of water into the side wall of the deep foundation pit and causing the problem of the overturning of the protection structure. The sediment deposited by the sedimentation layer 120, the first filter layer 200 and the second filter layer 210 can be used for construction.

[0052] In the above technical solution, the construction method of the coastal bridge deep foundation pit protection structure includes the following steps:

[0053] Step 1: Use concrete pouring to form the first support and the second support; among them, a plurality of first grouting pipes are arranged on the first support, and a plurality of second grouting pipes are arranged on the second support; on the first support, a spiral-shaped first diversion channel and a second diversion channel are formed by concrete pouring using a support formwork, and a sedimentation layer is arranged between the first diversion channel and the second diversion channel;

[0054] Step 2: Pour concrete to form the water-conducting layer of the receiving platform. The water-conducting layer is a trough-shaped structure. One end of the water-conducting layer away from the catch basin is a concrete column structure supporting a first filter layer thereon, and a second filter layer is supported by steel bars at the end close to the catch basin. A first sediment filter screen is arranged on the first filter layer, and a second sediment filter screen is arranged on the second filter layer. A first water-blocking structure is arranged on three peripheries of the first filter layer, and a second water-blocking structure is arranged on three peripheries of the second filter layer.

[0055] Step 3: Measure and set out the lines, excavate a protection area on the side wall of the deep foundation pit, and lay a bottom plate at the bottom of the protection area.

[0056] Step 4: Set a sand-passing structure at the lower end of each support column, connect multiple diversion columns with multiple support columns to form a lower diversion structure, and arrange the diversion structure on the bottom plate. Arrange the receiving platform on the diversion structure, and connect the first support body and the second support body to the receiving platform respectively according to the set angles. Among them, the first support body and the receiving platform, and the receiving platform and the second support body are connected by means of mortise and tenon joints. Lay a siphon pipe from the end of the diversion column to the end of the support column until one end of the siphon pipe is 1-3 cm away from the sand-passing structure.

[0057] Step 5: Inject slurry into the gaps between the deep foundation pit and the first support body, the receiving platform, and the second support body through multiple first grouting pipes and multiple second grouting pipes. Among them, the slurry for grouting is a mixture of HSC slurry and epoxy resin slurry, and the mass ratio of the epoxy resin slurry is 20%.

[0058] Step 6: Remove the bottom plate after the slurry solidifies.

[0059] Among them, the production method of HSC slurry includes: HSC slurry (water-containing fine sand type) is prepared by a high-speed slurry mixer, where the rotation speed of the slurry mixer is 1000-1200 r / min, the water-cement weight ratio is 1.3, and the slurry stirring time is 5 min. The production method of epoxy resin slurry includes: use a low-speed stirrer to fully stir epoxy resin and curing agent diethylenetriamine for 5 min, and then add strong mortar while stirring until a uniform thick slurry is formed. Among them, the mass ratio of epoxy resin, curing agent and mortar is 1:1:20, the grouting pressure is 0.8 MPa, and the model of the high-speed slurry mixer is ZJY400.

[0060] In another technical solution, such as Figure 1 , Figure 4 and Figure 5 , the deep foundation pit protection structure of the coastal bridge further includes:

[0061] Multiple support columns 4, which are vertically arranged at intervals below the receiving platform;

[0062] A plurality of diversion columns 5, which are horizontally arranged on both sides of the support column 4, one end of the diversion column 5 is communicated with the connected support column, and the other end extends to the sump;

[0063] Among them, the top of the support column 4 close to the first support body 1 is connected to the first support body 1 through two first reinforcing ribs 9, and the top of the support column 4 close to the second support body 3 is connected to the second support body 3 through two second reinforcing ribs 10; a sand passing structure 400 is provided at the lower end of each support column 4, and a plurality of sand screening holes 410 are provided on the sand passing structure 400.

[0064] In the above technical solution, in order to prevent the groundwater near the coast from seeping into the protection structure through the bottom of the protection structure during the deep excavation of the deep foundation pit, a plurality of support columns 4 are arranged along the central axis at the lower end of the receiving platform 2, and diversion columns 5 are alternately arranged on the left or right of each support column 4. One end of the diversion column 5 is communicated with the connection part of the support column 4 by welding, and the other end extends to the sump arranged around the deep foundation pit. The lowermost end of the support column 4 is exposed at the lower part of the cast support structure, so that it contacts the soil layer of the deep foundation pit to keep the pipeline unblocked. During the excavation of the deep foundation pit, the groundwater generated enters the inside of the support column 4 through the lower opening of the support column 4. As the excavation depth of the deep foundation pit increases, the water flow increases, and the water gradually rises to the diversion column 5 along the bottom of the support column 4 and flows into the sump arranged around the deep foundation pit from the diversion columns 5 arranged in two directions, avoiding the problem that the groundwater generated during the construction of the deep foundation pit seeps into the deep foundation pit protection structure from bottom to top, causing the collapse and overturning of the deep foundation pit protection structure. By arranging a sand passing structure 400 at the lower end of each support column 4, the filtration of sand and gravel in the groundwater is realized, and the suction of the support column and the diversion column is avoided to cause pipeline blockage.

[0065] In another technical solution, as Figure 1 shown, the deep foundation pit protection structure of the coastal bridge further includes:

[0066] A plurality of siphons 6, which are correspondingly arranged in a plurality of support columns 4, one siphon 6 is arranged in each support column 4, the siphon 6 has an "L" - shaped structure, one end of the siphon 6 extends to the bottom of the support column 4 and is located above the sand passing structure 400, and the other end extends to the diversion column 5, and the distance between one end of the siphon 6 and the sand passing structure 400 is 1 - 3 cm.

[0067] In the above embodiments, by arranging a siphon tube 6 in the support column 4 and the diversion column 5, the groundwater generated during the construction of the deep foundation pit is quickly sucked into the sump through the siphon principle, avoiding the collapse of the protective structure caused by the long-term immersion of the bottom of the deep foundation pit. When groundwater is generated during the construction of the deep foundation pit, the air in the siphon tube 6 is evacuated through the opening of the siphon tube 6 extending to the end of the diversion column 5. Since the air pressure at this end becomes smaller, using the siphon principle, the water at the end of the support column 4 will be sucked into the sump connected to the diversion column 5 through the siphon tube 6, realizing the rapid suction of groundwater at the protective structure and avoiding the collapse and overturning of the deep foundation pit protective structure as the groundwater level rises.

[0068] In another technical solution, as Figure 3 shown, the deep foundation pit protection structure of the coastal bridge further includes:

[0069] A first water retaining structure 7, which is arranged around the first filter layer 200 on three peripheries that are not connected to the first diversion groove 100;

[0070] A second water retaining structure 8, which is arranged around the second filter layer 210 on three peripheries that are not connected to the second diversion groove 110.

[0071] In the above technical solution, the first water retaining structure 7 is to block the water flowing down from the first diversion groove 100 from flowing to the left, front and right, and the second water retaining structure 8 is to block the water flowing down from the second diversion groove 110 from flowing to the left, front and right, so that the water flowing down from the first diversion groove 100 is filtered through the first filter layer 200 and then flows into the lower water guiding layer 220, and the water flowing down from the second diversion groove 110 is filtered through the second filter layer 210 and then flows into the lower water guiding layer 220 and finally converges and flows into the sump connected to it from the right opening of the water guiding layer 220. Among them, the connection between the first water retaining structure 7 and the first diversion groove 100, and the second baffle structure 8 and the second diversion groove 110 is a sealed fixed connection. The heights of the first water retaining structure 7 and the second water retaining structure 8 are set to 0.3 - 1 m, and their materials can be concrete structures or other waterproof structures.

[0072] In another technical solution, as Figure 1 shown, the deep foundation pit protection structure of the coastal bridge further includes:

[0073] A plurality of first grouting pipes 11, which are arranged at intervals on the first support 1. One end of any first grouting pipe 11 protrudes from the first support 1, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the first support 1;

[0074] A plurality of second grouting pipes 12 are arranged at intervals on the second support 3. One end of any second grouting pipe 12 protrudes from the second support 3, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the second support 3.

[0075] In the above technical solution, slurry is injected into the soil layer of the deep foundation pit corresponding to the first support 1 through a plurality of first grouting pipes 11 to form a corresponding casting support structure at the corresponding position between the first support 1 and the side wall of the deep foundation pit. Slurry is injected into the soil layer of the deep foundation pit corresponding to the second support 3 through a plurality of second grouting pipes 12 to form a corresponding casting support structure at the corresponding position between the second support 3 and the side wall of the deep foundation pit, so as to fix and support the first support 1, the receiving platform 2, and the second support 3.

[0076] In another technical solution, first hinge rings are respectively arranged on both sides of any first reinforcing rib 9, and the first hinge rings are hinged to the top ends of the first support 1 and the support column 4. Second hinge rings are respectively arranged on both sides of any second reinforcing rib 10, and the second hinge rings are hinged to the top ends of the second support 3 and the support column 4.

[0077] In the above technical solution, the first support 1 and the adjacent support column 4 are connected by both ends of the first hinge ring, and the second support 3 and the adjacent support column 4 are connected by both ends of the second hinge ring, so as to improve the connection strength of the protection structure.

[0078] This technical solution may also include the following technical details to better achieve the technical effect:

[0079] A construction method for a deep foundation pit protection structure of a coastal bridge includes:

[0080] Step 1: The first support and the second support are formed by concrete pouring. Among them, a plurality of first grouting pipes are arranged on the first support, and a plurality of second grouting pipes are arranged on the second support. A spiral first diversion groove and a second diversion groove are formed on the first support by concrete casting through a support formwork, and a sedimentation layer is erected between the first diversion groove and the second diversion groove.

[0081] Step 2: A water guide layer of the receiving platform is formed by concrete casting. The water guide layer is a trough-shaped structure. One end of the water guide layer far from the water collecting pool is a concrete column structure supporting a first filter layer thereon, and the end close to the water collecting pool is supported by steel bars for a second filter layer. A first sediment filter screen is arranged on the first filter layer, and a second sediment filter screen is arranged on the second filter layer. A first water retaining structure is arranged on three peripheries of the first filter layer, and a second water retaining structure is arranged on three peripheries of the second filter layer.

[0082] Step 3: Measuring and setting out lines. Excavate a protection area on the side wall of the deep foundation pit, and arrange a bottom plate at the bottom of the protection area.

[0083] Step 4: Set a sand-passing structure at the lower end of each support column. Connect multiple diversion columns with multiple support columns to form a lower diversion structure, and arrange the diversion structure on the bottom plate. Arrange a receiving platform on the diversion structure, and connect the first support body and the second support body to the receiving platform respectively according to the set angles. Among them, the first support body and the receiving platform, and the receiving platform and the second support body are connected by means of mortise and tenon joints. Lay a siphon tube from the end of the diversion column to the end of the support column until one end of the siphon tube is 1-3 cm away from the sand-passing structure.

[0084] Step 5: Inject slurry into the gaps between the deep foundation pit and the first support body, the receiving platform, and the second support body through multiple first grouting pipes and multiple second grouting pipes. Among them, the slurry for grouting is a mixture of HSC slurry and epoxy resin slurry, and the mass ratio of the epoxy resin slurry is 20%.

[0085] Step 6: Remove the bottom plate after the slurry has solidified.

[0086] Among them, the production method of HSC slurry includes: HSC slurry (water-containing fine sand type) is prepared by a high-speed pulp making machine, where the rotation speed of the pulp making machine is 1000-1200 r / min, the water-cement weight ratio is 1.3, and the slurry stirring time is 5 min. The production method of epoxy resin slurry includes: using a low-speed stirrer to fully stir epoxy resin and curing agent diethylenetriamine for 5 min, and then adding strong mortar while stirring until a uniform thick slurry is formed. Among them, the mass ratio of epoxy resin, curing agent, and mortar is 1:1:20, the grouting pressure is 0.8 MPa, and the model of the high-speed pulp making machine is ZJY400.

[0087] In the above technical solution, by using a slurry prepared by mixing HSC slurry and epoxy resin grouting material in a certain proportion, the strength of the protection structure is ensured, and the waterproof performance of the deep foundation pit protection structure is realized due to the water-curing and swelling characteristics of the epoxy resin grouting material.

[0088] The equipment quantity and treatment scale described here are used to simplify the description of the present invention. The application, modification, and variation of the deep foundation pit protection structure of the coastal bridge of the present invention are obvious to those skilled in the art.

[0089] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details and the illustrated and described examples here.

Claims

1. Coastal bridge deep foundation pit protection structure, characterized in that Comprising: A first support body, which is formed by pouring concrete, and the first support body is supported on the side wall of the deep foundation pit at an angle of 30 degrees to the vertical direction; A receiving platform, which is formed by pouring concrete, and the receiving platform is connected to the lower end of the first support body; A second support body, which is formed by pouring concrete, and the second support body is connected to the lower end of the receiving platform, and the second support body is arranged at an angle of 150 degrees to the horizontal plane of the receiving platform; Wherein, the first support body is provided with a first diversion groove and a second diversion groove extending from top to bottom, the first diversion groove and the second diversion groove are spiral, a sedimentation layer is arranged between the first diversion groove and the second diversion groove, a water guiding structure is arranged on the receiving platform, the water guiding structure includes a first filter layer, a second filter layer and a water guiding layer, the water guiding layer is located below the first filter layer and the second filter layer, the first filter layer is communicated with the first diversion groove, the second filter layer is communicated with the second diversion groove, a first sediment filter screen is arranged on the first filter layer, and a second sediment filter screen is arranged on the second filter layer; the water guiding layer is communicated with a water collecting pool arranged around the deep foundation pit; A plurality of support columns, which are vertically arranged at intervals below the receiving platform; A plurality of diversion columns, which are horizontally arranged on both sides of the support columns, one end of the diversion column is communicated with the connected support column, and the other end extends to the water collecting pool; Wherein, the top of the support column close to the first support body is connected to the first support body through 2 first reinforcing bars, and the top of the support column close to the second support body is connected to the second support body through 2 second reinforcing bars; a sand passing structure is arranged at the lower end of each support column, and a plurality of sand screening holes are arranged on the sand passing structure.

2. The coastal bridge deep foundation pit protection structure according to claim 1, characterized in that, Further comprising: A plurality of siphons, which are correspondingly arranged in a plurality of support columns, one siphon is arranged in each support column, the siphon is in an "L" - shaped structure, one end of the siphon extends to the bottom of the support column and is located above the sand passing structure, and the other end extends to the diversion column, and one end of the siphon is 1 - 3 cm away from the sand passing structure.

3. The coastal bridge deep foundation pit protection structure according to claim 1, characterized in that, Further comprising: A first water - blocking structure, which is arranged around the first filter layer on its three peripheries not connected to the first diversion groove; A second water - blocking structure, which is arranged around the second filter layer on its three peripheries not connected to the second diversion groove.

4. The coastal bridge deep foundation pit protection structure according to claim 1, characterized in that, Further comprising: A plurality of first grouting pipes, which are arranged at intervals on the first support body, one end of any first grouting pipe protrudes from the first support body, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the first support body; A plurality of second grouting pipes, which are arranged at intervals on the second support body, one end of any second grouting pipe protrudes from the second support body, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the second support body.

5. The coastal bridge deep foundation pit protection structure according to claim 1, characterized in that, On both sides of any first reinforcing bar, first hinge rings are respectively arranged, the first hinge rings are hinged to the top of the first support body and the support column, on both sides of any second reinforcing bar, second hinge rings are respectively arranged, and the second hinge rings are hinged to the top of the second support body and the support column.

6. A construction method of the deep foundation pit protection structure of the coastal bridge as described in claim 5, characterized in that, Including the following steps: Step 1: Use concrete pouring to form the first support body and the second support body; among them, a plurality of first grouting pipes are arranged on the first support body, and a plurality of second grouting pipes are arranged on the second support body; on the first support body, a spiral first diversion groove and a second diversion groove are formed by concrete pouring through a support formwork, and a sedimentation layer is erected between the first diversion groove and the second diversion groove; Step 2: Use concrete pouring to form the water guide layer of the receiving platform. The water guide layer is a trough-shaped structure. One end of the water guide layer far from the water collection pool is a concrete column structure supporting the first filter layer thereon. The end close to the water collection pool is supported by steel bars for the second filter layer. A first sediment filter screen is arranged on the first filter layer, and a second sediment filter screen is arranged on the second filter layer; a first water retaining structure is arranged on three peripheries of the first filter layer, and a second water retaining structure is arranged on three peripheries of the second filter layer; Step 3: Measure and set out the lines, excavate a protection area on the side wall of the deep foundation pit, and arrange a bottom plate at the bottom of the protection area; Step 4: Set a sand passing structure at the lower end of each support column, connect a plurality of diversion columns with a plurality of support columns to form a lower diversion structure, and arrange the diversion structure on the bottom plate; arrange a receiving platform on the diversion structure, and connect the first support body and the second support body to the receiving platform respectively according to the set angles; among them, the first support body and the receiving platform, and the receiving platform and the second support body are connected by means of groove and tenon joints; lay a siphon tube from the diversion column end to the support column end until one end of the siphon tube is 1-3 cm away from the sand passing structure; Step 5: Grout into the gaps between the deep foundation pit and the first support body, the receiving platform, and the second support body through a plurality of first grouting pipes and a plurality of second grouting pipes; Step 6: Remove the bottom plate after the slurry solidifies.

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