WO2025232103A1 - Coastal bridge deep foundation pit protection structure and construction method - Google Patents

Abstract

Disclosed in the present invention is a coastal bridge deep foundation pit protection structure, comprising: a first support body, which is formed by concrete casting in place, the first support body being supported on a side wall of a deep foundation pit with the angle between the first support body and the vertical direction being 30 degrees; a bearing platform, which is formed by concrete casting in place, the bearing platform being connected to the lower end of the first support body; and a second support body, which is formed by concrete casting in place, the second support body being connected to the lower end of the bearing platform, and the angle between the second support body and the horizontal plane of the bearing platform being 150 degrees. The bearing platform is provided with a water guide structure; the top of the first support body is provided with a plurality of mounting seats which are spaced apart; and one end of each of a plurality of flow-guiding grooves is arranged on a mounting seat, and the other end extends to the water guide structure. Aiming at the particularity of coastal geology, the present invention can avoid the problem of overturning of protection structures caused by the infiltration of water into side walls of deep foundation pits during the excavation of the deep foundation pits.

Description

Protection Structure and Construction Method for Deep Foundation Pit of Coastal Bridge Technical Field

This invention relates to the field of coastal bridge construction technology. More specifically, this invention relates to a protective structure and construction method for deep foundation pits in coastal bridges.

Background Technology

Coastal bridge construction areas are mostly composed of clay, sand, sandy clay, and gravelly clay, and may also contain "V-shaped" and "U-shaped" valleys, resulting in limited construction space. Current deep foundation pit construction often employs support structures to protect the sidewalls of the pit, ensuring construction safety and the safety of surrounding buildings. However, deep foundation pit support structures for coastal bridge projects lack permeable and drainage structures. This can easily lead to soil slippage at the lower end of the pit sidewalls during construction, causing the entire support structure to overturn, thus affecting its safety and stability. For example, application number 202323595242.3, entitled "A Deep Foundation Pit Support Structure," includes several steel pipe columns vertically fixed to the bottom of the deep foundation pit and evenly spaced along its length. A retaining plate is fixed between the steel pipe columns and the slope of the deep foundation pit, and backfill soil is fixed between the retaining plate and the slope of the deep foundation pit. It achieves its support function through a combination of several steel pipe columns, retaining plates and backfill soil. However, deep foundation pit protection for coastal bridges is prone to problems such as water seepage and overturning of the support structure.

Summary of the Invention

One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

Another objective of this invention is to provide a protective structure for deep foundation pits of coastal bridges, which can provide effective protection during the excavation of deep foundation pits.

To achieve these objectives and other advantages according to the present invention, a deep foundation pit protection structure for coastal bridges is provided, comprising:

The first support structure is made of concrete and is supported on the side wall of the deep foundation pit at a 30-degree angle to the vertical direction.

The receiving platform is made of concrete and is connected to the lower end of the first support body.

The second support is made of concrete and is connected to the lower end of the support platform. The second support is set at a 150-degree angle to the horizontal plane of the support platform.

The first support body extends from top to bottom and is provided with a first guide channel and a second guide channel. The first and second guide channels are spiral-shaped, and a sedimentation layer is provided between the first and second guide channels. A water guiding structure is provided 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 connected to the first guide channel, and the second filter layer is connected to the second guide channel. A first sediment filter screen is provided on the first filter layer, and a second sediment filter screen is provided on the second filter layer. The water guiding layer is connected to a water collection pool set around the deep foundation pit.

Preferably, the deep foundation pit protection structure for coastal bridges further includes:

Multiple support columns are vertically spaced below the receiving platform;

Multiple guide columns are horizontally arranged on both sides of the support column, with one end of the guide column connected to the support column and the other end extending to the water collection tank.

The top of the support column located near the first support body is connected to the first support body by two first reinforcing ribs, and the top of the support column located near the second support body is connected to the second support body by two second reinforcing ribs; the lower end of each support column is provided with a sand-passing structure, and the sand-passing structure is provided with multiple sand-screening holes.

Preferably, the deep foundation pit protection structure for coastal bridges further includes:

Multiple siphon tubes are installed in multiple support columns, with one siphon tube installed in each support column. The siphon tubes are L-shaped, with one end extending to the bottom of the support column and above the sand-passing structure, and the other end extending to the guide column. One end of the siphon tube is 1 to 3 cm away from the sand-passing structure.

Preferably, the deep foundation pit protection structure for coastal bridges further includes:

The first water-blocking structure is disposed around the first filter layer on three peripheries that are not connected to the first flow channel;

The second water-blocking structure is arranged around the second filter layer on three peripheries that are not connected to the second flow channel.

Preferably, the deep foundation pit protection structure for coastal bridges further includes:

Multiple first grouting pipes are spaced apart 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. Inside;

Multiple second grouting pipes are spaced apart 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.

Preferably, each of the first reinforcing ribs has a first hinge ring on both sides, the first hinge ring being hinged to the top of the first support body and the support column; and each of the second reinforcing ribs has a second hinge ring on both sides, the second hinge ring being hinged to the top of the second support body and the support column.

This invention is further realized through a construction method for a deep foundation pit protection structure for coastal bridges, which includes the following steps:

Step 1: Concrete is used to form a first support body and a second support body; wherein, multiple first grouting pipes are arranged on the first support body and multiple second grouting pipes are arranged on the second support body; a spiral first guide channel and a second guide channel are formed on the first support body by concrete pouring through a support template, and a sedimentation layer is erected between the first guide channel and the second guide channel.

Step 2: Concrete is used to form the water-guiding layer of the receiving platform. The water-guiding layer has a trough-shaped structure. The end of the water-guiding layer away from the water collection pool is supported by a concrete column structure for the first filter layer. The end closer to the water collection pool is supported by steel bars for the second filter layer. A first silt filter screen is installed on the first filter layer, and a second silt filter screen is installed on the second filter layer. A first water-blocking structure is installed around the three perimeters of the first filter layer, and a second water-blocking structure is installed around the three perimeters of the second filter layer.

Step 3: Measure and set out the lines. Excavate a protective zone on the side wall of the deep foundation pit and place a base plate at the bottom of the protective zone.

Step 4: Install a sand-passing structure at the lower end of each support column, connecting multiple guide columns and multiple support columns to form a lower guide structure, and arrange the guide structure on the base plate; arrange a receiving platform on the guide structure, and connect the first support body and the second support body to the receiving platform according to the set angle; wherein, 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; install a siphon pipe from the end of the guide 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;

Step 5: Grout the gap 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;

Step 6: Remove the base plate after the slurry has solidified.

The present invention has at least the following beneficial effects:

1. In view of the special characteristics of coastal geology, the deep foundation pit protection structure is designed as an integral sloping structure, which facilitates the flow of rainwater and other construction water into the water guiding structure of the receiving platform through the first and second guide channels designed on the first support body. The two ends of the water guiding structure are connected to the water collection pool of the deep foundation pit, and then flow into the water collection pool, thus avoiding the seepage of water into the side wall of the deep foundation pit and the problem of the protective structure overturning.

2. The first and second diversion channels are spiral-shaped. When the rain is heavy, the energy of the water flow is dissipated and the water flow speed is slowed down, reducing its ability to scour and damage the receiving platform. By setting a sedimentation layer between the first and second diversion channels, the sand and gravel washed by the rainwater are deposited for the first time.

3. By setting up multiple support columns and guide columns below the receiving platform, with one end of the guide columns extending to the water collection pool, the problem of groundwater generated during the deep foundation pit construction process is prevented from seeping into the deep foundation pit protection structure from bottom to top, thus avoiding the collapse and overturning of the deep foundation pit protection structure.

4. By setting a sand-filtering structure at the lower end of each support column, sand and gravel in the groundwater can be filtered out, preventing the pipes from being blocked by the support columns and guide columns.

5. By installing siphon pipes inside the support columns and guide columns, the groundwater generated during the construction of the deep foundation pit is quickly drawn into the collection pool through the siphon principle, avoiding the collapse of the protective structure caused by prolonged soaking of the bottom of the deep foundation pit.

6. A first water-blocking structure is provided around the three perimeters of the first filter layer, and a second water-blocking structure is provided around the three perimeters of the second filter layer to prevent water from overflowing the water guiding structure and flowing into the deep foundation pit.

Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention.

Attached Figure Description

Figure 1 is a structural schematic diagram of the deep foundation pit protection structure for shore bridges according to a technical solution of the present invention;

Figure 2 is a schematic diagram of the structure of the first guide channel and the second guide channel in another technical solution of the present invention;

Figure 3 is a schematic diagram of the water-guiding structure in another technical solution of the present invention;

Figure 4 is a schematic diagram of the structure of a single support column and a guide column in another technical solution of the present invention;

Figure 5 is a schematic diagram of the arrangement of multiple support columns and guide columns in another technical solution of the present invention;

Reference numerals in the attached drawings: 1: First support body; 100: First guide channel; 110: Second guide channel; 120: Sedimentation layer; 2: Receiving platform; 200: First filter layer; 210: Second filter layer; 220: Water guiding layer; 230: First silt filter screen; 240: Second silt filter screen; 3: Second support body; 4: Support column; 400: Sand-passing structure; 410: Sand-screening hole; 5: Guide column; 6: Siphon pipe; 7: First water-blocking structure; 8: Second water-blocking structure; 9: First reinforcing rib; 10: Second reinforcing rib; 11: First grouting pipe; 12: Second grouting pipe.

Detailed Implementation

The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

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 combinations thereof.

As shown in Figures 1-3, the present invention provides a deep foundation pit protection structure for coastal bridges, comprising:

The first support body 1 is made of concrete and is supported on the side wall of the deep foundation pit at a 30-degree angle to the vertical direction.

The receiving platform 2 is made of concrete and is connected to the lower end of the first support body 1.

The second support 3 is made of concrete. The second support 3 is connected to the lower end of the receiving platform 2. The second support 3 is set at a 150-degree angle to the horizontal plane of the receiving platform 2.

The first support body 1 extends from top to bottom and is provided with a first guide channel 100 and a second guide channel 110. The first guide channel 100 and the second guide channel 110 are spiral in shape. A sedimentation layer 120 is provided between the first guide channel 100 and the second guide channel 110. A water guiding structure is provided 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 connected to the first guide channel 100 and the second filter layer 210 is connected to the second guide channel 110. A first sediment filter screen 230 is provided on the first filter layer 200 and a second sediment filter screen 240 is provided on the second filter layer 210. The water guiding layer is connected to a water collection pool set around the deep foundation pit.

In the above technical solution, the side wall of the first support 1 near the deep foundation pit forms a 30° angle with the vertical direction. An angled support is installed on the sidewall of the deep foundation pit. The top of the first support body 1 is connected to the sidewall of the deep foundation pit by a mortise and tenon joint with a concrete slab. The lower end of the first support body is connected to one end of the support platform by a mortise and tenon joint, and the other end of the support platform is connected to the upper end of the second support body 3 by a mortise and tenon joint. The three parts are connected to form an integral structure that supports the cast-in-place support structure as a protective structure for the sidewall of the deep foundation pit. A first guide channel 100 and a second guide channel 110 extend from the top to the bottom of the first support body 1. The first guide channel 100 and the second guide channel 110 are set in a spiral shape. When the rainfall is heavy, the energy of the water flow is dissipated and the water flow speed is slowed down, reducing its ability to scour and damage the support platform. A sedimentation layer 120 is set between the first guide channel 100 and the second guide channel 110 to initially deposit the sand and gravel washed by the rainwater. The first guide channel 100 and the second guide channel 110 form a flat structure at the location where the sedimentation layer 120 is constructed. The sedimentation layer 120 is fixed by drilling holes in the first guide channel 100 and the second guide channel 110. A first filter layer 200 is provided on the receiving platform corresponding to the position of the first guide channel 100 to filter and deposit silt in the rainwater flowing down from the first guide channel 100. A second filter layer 210 is provided on the receiving platform corresponding to the position of the second guide channel 110 to filter and deposit silt in the rainwater flowing down from the second guide channel 110. One end of the water guiding structure is positioned corresponding to the first guide channel 100, and the other end extends above the water collection pool set around the deep foundation pit. To address the unique characteristics of coastal geology, the deep foundation pit protection structure is designed as a sloping structure. This facilitates the flow of rainwater and other construction-generated water through the first guide channel 100 and the second guide channel 110 on the first support body into the water-guiding structure of the receiving platform 2. One end of the water-guiding structure is connected to the water collection pool of the deep foundation pit, preventing water from seeping into the sidewalls of the deep foundation pit and causing the protection structure to overturn. The sediment deposited through the settling layer 120, the first filter layer 200, and the second filter layer 210 can be used for construction.

In the above technical solution, the construction method of the deep foundation pit protection structure for coastal bridges includes the following steps:

Step 1: Concrete is used to form a first support body and a second support body; wherein, multiple first grouting pipes are arranged on the first support body and multiple second grouting pipes are arranged on the second support body; a spiral first guide channel and a second guide channel are formed on the first support body by concrete pouring through a support template, and a sedimentation layer is erected between the first guide channel and the second guide channel.

Step 2: Concrete is poured to form the water-guiding layer of the receiving platform. The water-guiding layer has a trough-shaped structure. At the end of the water-guiding layer furthest from the collection tank, a first filter layer is supported by a concrete column structure. At the end closer to the collection tank, a second filter layer is supported by steel reinforcement. A first sediment filter screen is installed on the first filter layer, and the second filter... A second sediment filter screen is provided on the filter layer; a first water-blocking structure is provided around the three peripheries of the first filter layer, and a second water-blocking structure is provided around the three peripheries of the second filter layer.

Step 3: Measure and set out the lines. Excavate a protective zone on the side wall of the deep foundation pit and place a base plate at the bottom of the protective zone.

Step 4: Install a sand-passing structure at the lower end of each support column, connecting multiple guide columns and multiple support columns to form a lower guide structure, and arrange the guide structure on the base plate; arrange a receiving platform on the guide structure, and connect the first support body and the second support body to the receiving platform according to the set angle; wherein, 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; install a siphon pipe from the end of the guide 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;

Step 5: Grouting is performed through multiple first grouting pipes and multiple second grouting pipes into the gaps between the deep foundation pit and the first support, the receiving platform, and the second support; wherein, the grouting slurry is a mixture of HSC grout and epoxy resin slurry, wherein the epoxy resin slurry accounts for 20% of the mass.

Step 6: Remove the base plate after the slurry has solidified.

The preparation method of HSC grout includes: HSC grout (water-containing fine sand type) is prepared using a high-speed pulping machine, wherein the pulping machine speed is 1000-1200 r/min, the water-cement weight ratio is 1.3, and the grout mixing time is 5 min. The preparation method of epoxy resin grout includes: using a low-speed mixer to fully mix epoxy resin and curing agent diethylenetriamine for 5 min, then adding strong mortar while stirring until a homogeneous thick grout is formed; wherein the mass ratio of epoxy resin, curing agent and mortar is 1:1:20, the grouting pressure is 0.8 MPa, and the high-speed pulping machine model is ZJY400.

In another technical solution, as shown in Figures 1, 4, and 5, the deep foundation pit protection structure for coastal bridges further includes:

Multiple support columns 4 are vertically spaced below the receiving platform;

Multiple guide columns 5 are horizontally arranged on both sides of the support column 4. One end of the guide column 5 is connected to the support column and the other end extends to the water collection tank.

The top of the support column 4 located near the first support body 1 is connected to the first support body 1 by two first reinforcing ribs 9, and the top of the support column 4 located near the second support body 3 is connected to the second support body 3 by two second reinforcing ribs 10; the lower end of each support column 4 is provided with a sand-passing structure. 400, the sand-passing structure 400 is provided with a plurality of sand-screening holes 410.

In the above technical solution, to prevent groundwater near the coast from seeping into the protective structure through the bottom of the protective structure during the deep foundation pit excavation process, multiple support columns 4 are set along the central axis at the lower end of the support platform 2. Guide columns 5 are alternately set to the left or right of each support column 4. One end of the guide column 5 is connected to the support column 4 by welding, and the other end extends into the water collection pool set around the deep foundation pit. The lowest end of the support column 4 is exposed at the bottom of the cast-in-place support structure, allowing it to contact the soil layer of the deep foundation pit and maintain unobstructed flow. Groundwater generated during the deep foundation pit excavation enters the support column 4 through the opening at the lower end of the support column 4. As the excavation depth increases, the water flow increases, and the water gradually rises along the bottom of the support column 4 to the guide column 5. From the guide columns 5 set in two directions, the water flows into the water collection pool set around the deep foundation pit, preventing groundwater generated during the deep foundation pit construction from seeping upwards into the deep foundation pit protective structure and causing the deep foundation pit protective structure to collapse and overturn. By setting a sand-filtering structure 400 at the lower end of each support column 4, sand and gravel in the groundwater can be filtered, preventing the pipes from being blocked by the intake of the support columns and guide columns.

In another technical solution, as shown in Figure 1, the deep foundation pit protection structure for coastal bridges further includes:

Multiple siphon tubes 6 are correspondingly installed in multiple support columns 4, with one siphon tube 6 installed in each support column 4. The siphon tube 6 has an "L" shaped structure. One end of the siphon tube 6 extends to the bottom of the support column 4 and is located above the sand-passing structure 400, while the other end extends to the guide column 5. The distance between one end of the siphon tube 6 and the sand-passing structure 400 is 1 to 3 cm.

In the above implementation scheme, by installing siphon pipes 6 inside the support column 4 and the guide column 5, groundwater generated during the construction of the deep foundation pit is quickly drawn into the collection pool using the siphon principle, avoiding prolonged soaking of the bottom of the deep foundation pit and thus preventing the collapse of the protective structure. When groundwater is generated during the construction of the deep foundation pit, the air inside the siphon pipe 6, which extends to the end of the guide column 5, is evacuated. Due to the reduced air pressure at this end, water located at the end of the support column 4 is drawn into the collection pool connected to the guide column 5 through the siphon pipe 6, achieving rapid extraction of groundwater from the protective structure and preventing the deep foundation pit protective structure from collapsing and overturning as the groundwater level rises.

In another technical solution, as shown in Figure 3, the deep foundation pit protection structure for coastal bridges further includes:

The first water-blocking structure 7 is disposed around the first filter layer 200 on three peripheries that are not connected to the first flow channel 100;

The second water-blocking structure 8 is disposed around the second filter layer 210 when it is not connected to the second flow guide channel. 110 connects to the three surrounding areas.

In the above technical solution, the first water-blocking structure 7 is used to block the water flowing down from the first guide channel 100 from flowing to the left, front end and right. The second water-blocking structure 8 is used to block the water flowing down from the second guide channel 110 from flowing to the left, front end and right. The water flowing down from the first guide channel 100 is filtered by the first filter layer 200 and flows into the lower water guide layer 220. The water flowing down from the second guide channel 110 is filtered by the second filter layer 210 and flows into the lower water guide layer 220. Finally, the water flows into the water collection pool connected to the water guide layer 220 from the right opening of the water guide layer 220. The connection between the first water-blocking structure 7 and the first guide channel 100, the second baffle structure 8 and the second guide channel 110 is a sealed connection. The height of the first water-blocking structure 7 and the second water-blocking structure 8 is set to 0.3~1m. The material can be concrete structure or other waterproof structure.

In another technical solution, as shown in Figure 1, the deep foundation pit protection structure for coastal bridges further includes:

Multiple first grouting pipes 11 are spaced apart on the first support body 1. One end of any first grouting pipe 11 protrudes from the first support body 1, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the first support body 1.

Multiple second grouting pipes 12 are spaced apart on the second support body 3. One end of any second grouting pipe 12 protrudes from the second support body 3, and the other end is vertically inserted into the soil layer of the deep foundation pit corresponding to the second support body 3.

In the above technical solution, grout is injected into the soil layer of the deep foundation pit corresponding to the first support body 1 through multiple first grouting pipes 11 to form a corresponding cast-in-place support structure at the corresponding position of the first support body 1 and the side wall of the deep foundation pit. Grout is injected into the soil layer of the deep foundation pit corresponding to the second support body 3 through multiple second grouting pipes 12 to form a corresponding cast-in-place support structure at the corresponding position of the second support body 3 and the side wall of the deep foundation pit, thereby achieving the fixation and support of the first support body 1, the receiving platform 2, and the second support body 3.

In another technical solution, a first hinge ring is provided on both sides of any first reinforcing rib 9, and the first hinge ring is hinged to the top of the first support body 1 and the support column 4. A second hinge ring is provided on both sides of any second reinforcing rib 10, and the second hinge ring is hinged to the top of the second support body 3 and the support column 4.

In the above technical solution, the first support body 1 and its adjacent support column 4 are connected by the two ends of the first hinge ring, and the second support body 3 and its adjacent support column 4 are connected by the two ends of the second hinge ring, thereby improving the connection strength of the protective structure.

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

A construction method for a deep foundation pit protection structure for a coastal bridge includes:

Step 1: Concrete is used to form a first support body and a second support body; wherein, multiple first grouting pipes are arranged on the first support body and multiple second grouting pipes are arranged on the second support body; a spiral first guide channel and a second guide channel are formed on the first support body by concrete pouring through a support template, and a sedimentation layer is erected between the first guide channel and the second guide channel.

Step 2: Concrete is used to form the water-guiding layer of the receiving platform. The water-guiding layer has a trough-shaped structure. The end of the water-guiding layer away from the water collection pool is supported by a concrete column structure for the first filter layer. The end closer to the water collection pool is supported by steel bars for the second filter layer. A first silt filter screen is installed on the first filter layer, and a second silt filter screen is installed on the second filter layer. A first water-blocking structure is installed around the three perimeters of the first filter layer, and a second water-blocking structure is installed around the three perimeters of the second filter layer.

Step 3: Measure and set out the lines. Excavate a protective zone on the side wall of the deep foundation pit and place a base plate at the bottom of the protective zone.

Step 4: Install a sand-passing structure at the lower end of each support column, connecting multiple guide columns and multiple support columns to form a lower guide structure, and arrange the guide structure on the base plate; arrange a receiving platform on the guide structure, and connect the first support body and the second support body to the receiving platform according to the set angle; wherein, 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; install a siphon pipe from the end of the guide 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;

Step 5: Grouting is performed through multiple first grouting pipes and multiple second grouting pipes into the gaps between the deep foundation pit and the first support, the receiving platform, and the second support; wherein, the grouting slurry is a mixture of HSC grout and epoxy resin slurry, wherein the epoxy resin slurry accounts for 20% of the mass.

Step 6: Remove the base plate after the slurry has solidified.

The preparation method of HSC grout includes: HSC grout (water-containing fine sand type) is prepared using a high-speed pulping machine, wherein the pulping machine speed is 1000-1200 r/min, the water-cement weight ratio is 1.3, and the grout mixing time is 5 min. The preparation method of epoxy resin grout includes: using a low-speed mixer to fully mix epoxy resin and curing agent diethylenetriamine for 5 min, then adding strong mortar while stirring until a homogeneous thick grout is formed; wherein the mass ratio of epoxy resin, curing agent and mortar is 1:1:20, the grouting pressure is 0.8 MPa, and the high-speed pulping machine model is ZJY400.

In the above technical solution, the strength of the protective structure is ensured by using a grout prepared by mixing HSC grout and epoxy resin grout in a certain proportion, and the water-curing and expanding characteristics of epoxy resin grout enable the waterproof performance of the deep foundation pit protection structure.

The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the deep foundation pit protection structure for coastal bridges of this invention will be readily apparent to those skilled in the art.

Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims (7)

A deep foundation pit protection structure for coastal bridges, characterized in that it includes: The first support structure is made of concrete and is supported on the side wall of the deep foundation pit at a 30-degree angle to the vertical direction. The receiving platform is made of concrete and is connected to the lower end of the first support body. The second support is made of concrete and is connected to the lower end of the support platform. The second support is set at a 150-degree angle to the horizontal plane of the support platform. The first support extends from top to bottom and is provided with a first guide channel and a second guide channel, which are spiral in shape. A sedimentation layer is provided between the first guide channel and the second guide channel. A water guiding structure is provided 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 connected to the first guide channel, and the second filter layer is connected to the second guide channel. A first sediment filter screen is provided on the first filter layer, and a second sediment filter screen is provided on the second filter layer. The water guiding layer is connected to a water collection pool set around the deep foundation pit. The deep foundation pit protection structure for coastal bridges as described in claim 1, characterized in that it further comprises: Multiple support columns are vertically spaced below the receiving platform; Multiple guide columns are horizontally arranged on both sides of the support column, with one end of the guide column connected to the support column and the other end extending to the water collection tank. The top of the support column located near the first support body is connected to the first support body by two first reinforcing ribs, and the top of the support column located near the second support body is connected to the second support body by two second reinforcing ribs; the lower end of each support column is provided with a sand-passing structure, and the sand-passing structure is provided with multiple sand-screening holes. The deep foundation pit protection structure for coastal bridges as described in claim 2 is characterized in that it further comprises: Multiple siphon tubes are installed in multiple support columns, with one siphon tube installed in each support column. The siphon tubes are L-shaped, with one end extending to the bottom of the support column and above the sand-passing structure, and the other end extending to the guide column. One end of the siphon tube is 1 to 3 cm away from the sand-passing structure. The deep foundation pit protection structure for coastal bridges as described in claim 1, characterized in that it further comprises: The first water-blocking structure is disposed around the first filter layer on three peripheries that are not connected to the first flow channel; The second water-blocking structure is arranged around the second filter layer on three peripheries that are not connected to the second flow channel. The deep foundation pit protection structure for coastal bridges as described in claim 1, characterized in that it further comprises: Multiple first grouting pipes are spaced apart 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. Multiple second grouting pipes are spaced apart 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. The deep foundation pit protection structure for coastal bridges as described in claim 2 is characterized in that, a first hinge ring is provided on both sides of any first reinforcing rib, and the first hinge ring is hinged to the top of the first support body and the support column; a second hinge ring is provided on both sides of any second reinforcing rib, and the second hinge ring is hinged to the top of the second support body and the support column. A construction method for a deep foundation pit protection structure for a coastal bridge as described in claim 6, characterized by comprising the following steps: Step 1: Concrete is used to form a first support body and a second support body; wherein, multiple first grouting pipes are arranged on the first support body and multiple second grouting pipes are arranged on the second support body; a spiral first guide channel and a second guide channel are formed on the first support body by concrete pouring through a support template, and a sedimentation layer is built between the first guide channel and the second guide channel. Step 2: Concrete is used to form the water-guiding layer of the receiving platform. The water-guiding layer has a trough-shaped structure. The end of the water-guiding layer away from the water collection pool is supported by a concrete column structure for the first filter layer. The end closer to the water collection pool is supported by steel bars for the second filter layer. A first silt filter screen is installed on the first filter layer, and a second silt filter screen is installed on the second filter layer. A first water-blocking structure is installed around the three perimeters of the first filter layer, and a second water-blocking structure is installed around the three perimeters of the second filter layer. Step 3: Measure and set out the lines. Excavate a protective zone on the side wall of the deep foundation pit and place a base plate at the bottom of the protective zone. Step 4: Install a sand-passing structure at the lower end of each support column, connecting multiple guide columns and multiple support columns to form a lower guide structure, and arrange the guide structure on the base plate; arrange a receiving platform on the guide structure, and connect the first support body and the second support body to the receiving platform according to the set angle; wherein, 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; install a siphon pipe from the end of the guide 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; Step 5: Grout the gap 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; Step 6: Remove the base plate after the slurry has solidified.