Bridge anti-scouring pile foundation structure and construction method and disaster early warning method thereof

Abstract

The invention discloses a bridge anti-scouring pile foundation structure and a construction method and a disaster early warning method thereof, and belongs to the technical field of bridge pile foundation protection and disaster prevention and reduction. The structure comprises a pile foundation and a construction cofferdam top surface line, a scouring detection assembly is arranged on the side wall of the pile foundation and located on one side of the upstream upstream face, the scouring detection assembly is located on the lower side of a designed scouring line of the pile foundation and is arranged close to the designed scouring line, and the construction cofferdam top surface line is located above the designed scouring line. The scouring detection assembly is low in manufacturing cost and is directly installed on one side of the upstream upstream face of the side wall of the pile foundation, the installation stability and the detection accuracy of the scouring detection assembly are ensured, and the situations that the scouring detection assembly is disturbed by river water, so that the position changes and the detection accuracy is reduced are avoided; meanwhile, the outer circle face of the pile foundation is fully utilized for guiding flow of impurities such as soil and large stones carried by river water, and it is avoided that the impurities are gathered at the installation position of the scouring detection assembly, and consequently the accuracy of the detection result is reduced.

Description

Technical Field

[0001] The invention relates to a bridge anti-scour pile foundation structure and a construction method thereof and a disaster early warning method, belonging to the technical field of bridge pile foundation protection and disaster prevention and reduction. Background Art

[0002] When designing a bridge, the regional rainfall, hydrological and sediment characteristics, etc. are determined according to the requirements of relevant bridge design specifications, and the scour depth of the bridge pile foundation is calculated according to the design service life. The pile foundation above the scour depth line does not consider providing vertical bearing capacity and lateral embedding of the rock and soil. The pile foundation below the scour depth line is considered to provide vertical bearing capacity and lateral embedding of the rock and soil. Then the pile foundation diameter and length are determined according to the load size and geological conditions.

[0003] The bridge pile foundation mainly configures the main force reinforcement, spiral stirrups and concrete inside the pile foundation to bear the load together. The main reinforcement and stirrups are connected to each other to form a steel skeleton. The vertical force reinforcement is a certain distance away from the outer surface of the pile foundation concrete. This part of the concrete is the protective layer of the force reinforcement, which prevents the force reinforcement from being corroded by the external environment during use, ensures the bearing capacity of the steel bars, and ensures the safety of the bridge pile foundation structure, thereby ensuring the safety of the bridge structure. It is common for the bridge pile foundation arranged in the mountains to be located underwater, and the proportion is relatively high. The bridge pile foundation is mostly arranged in shallow water areas on the shore, and is mostly constructed in the dry season with shallow water depth. The pile foundation is mainly constructed by the island cofferdam method. In this case, the number of bridge pile foundations is large and the proportion is large. When constructing the underwater pile foundation island cofferdam, the main process is to first measure and locate the position, then build the island cofferdam to create an underwater pile foundation construction platform, drill holes according to the pile top elevation, install the steel cage, and pour underwater concrete.

[0004] During routine bridge inspections, when bridge pile foundation diseases are discovered, traffic is interrupted and bridges are renovated and reinforced, causing huge economic losses and social impacts. For bridges located in the mountains, during the rainy season, when rainfall is heavy, mountain gullies are prone to floods and debris flows, which seriously scour the bridge pile foundations. Debris flows carrying large rocks have a greater impact on the bridge pile foundations. Once the design standards and bearing capacity are exceeded, the bridge will collapse. After the bridge collapses, if there is no timely warning and control, it will cause great harm to people's lives and property.

[0005] A Chinese patent document with publication number CN103017674A discloses a cantilever bridge pier scour monitoring device based on a Bragg grating sensor, including a guard plate, which is fixedly connected to a steel plate, a resin layer located between the pair of guard plates, and the height of the guard plate is greater than the height of the resin layer. The provision of the guard plate can prevent the resin layer from being damaged by debris in the water, thereby protecting the Bragg grating sensor and the optical fiber, and ensuring the normal monitoring. In addition, the optical fiber and the Bragg grating sensor are wrapped with a resin layer adhesive to protect them from damage. At the same time, a number of steel bars are provided on the through groove of the hollow sleeve, which can directly prevent large debris, stones, drifting ice, etc. from entering the interior of the hollow sleeve, affecting the bending deformation of the steel plate and causing the Bragg grating sensor to read incorrectly. This ensures that the monitoring device of the present invention is not affected by monitoring under extreme weather conditions.

[0006] However, the manufacturing cost of the monitoring device is high, and the through slot on the hollow sleeve is easily blocked by debris such as soil and large stones, resulting in a decrease in the accuracy of the detection results of the monitoring device, and even causing the monitoring device to fail. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a bridge anti-scour pile foundation structure and a construction method thereof and a disaster early warning method.

[0008] The present invention is achieved through the following technical solutions:

[0009] A bridge anti-scour pile foundation structure comprises a pile foundation and a construction cofferdam top surface line, wherein a scour detection component is provided on the side wall of the pile foundation on the upstream water-facing side, and the scour detection component is located below the designed scour line of the pile foundation and arranged close to the designed scour line, and the construction cofferdam top surface line is located above the designed scour line.

[0010] The pile foundation includes poured concrete for the pile foundation and a steel skeleton arranged in the poured concrete for the pile foundation. The steel skeleton includes a plurality of longitudinal main stress-bearing bars, a plurality of reinforcing bars and spiral stirrups. The plurality of longitudinal main stress-bearing bars are arranged side by side, the plurality of reinforcing bars are connected to all the longitudinal main stress-bearing bars, and the reinforcing bars are located on the inner side of the area surrounded by all the longitudinal main stress-bearing bars. The spiral stirrups are connected to all the longitudinal main stress-bearing bars and are located on the outer side of the area surrounded by all the longitudinal main stress-bearing bars.

[0011] The scour detection component is a pressure sensor, which is arranged on the spiral stirrup and partially or completely exposed outside the poured concrete of the pile foundation.

[0012] The upper end of the pile foundation is provided with a pile foundation pedestal, and a steel plate casing is mounted on the pile foundation. The lower end of the steel plate casing extends to the designed scour line, and the upper end extends above the top surface line of the construction cofferdam and is coplanar with the bottom surface of the pile foundation pedestal.

[0013] The steel plate casing is coaxially arranged with the steel bar skeleton and is located outside the steel bar skeleton. The steel plate casing is connected with the spiral stirrups through a plurality of positioning steel bars.

[0014] A displacement sensor is provided on the side wall of the pile foundation at the upstream water-facing side. The displacement sensor is located on the inner side of the steel plate casing and is arranged close to the upper end of the steel plate casing.

[0015] The displacement sensor is arranged on the spiral stirrup.

[0016] It also includes a controller and a wireless transceiver module. The controller is electrically connected to the flushing detection component and the displacement sensor, and the wireless transceiver module is electrically connected to the controller.

[0017] A construction method for a bridge anti-scour pile foundation structure comprises the following steps:

[0018] Step 1: Determine the length and diameter of the pile foundation by calculation based on the survey results;

[0019] Step 2: Complete the flood and sediment characteristics survey and calculate and determine the location of the designed scour line;

[0020] Step 3: Determine the top elevation of the construction cofferdam according to the river water level during construction, that is, determine the position of the top line of the construction cofferdam, and then fill the cofferdam to form an underwater construction platform;

[0021] Step 4: According to the pile foundation coordinates, re-measure the position on the construction cofferdam and start the pile foundation drilling construction;

[0022] Step 5: After the drilling is completed, re-measure the hole depth and hole diameter to determine the elevation of the designed scour line and the elevation of the top line of the construction cofferdam;

[0023] Step 6: Weld the longitudinal main reinforcement, reinforcing bars and spiral stirrups to form a reinforcement skeleton;

[0024] Step 7: Install the steel skeleton section by section in the holes of the pile foundation;

[0025] Step 8: Weld and fix the steel plate casing to the steel frame by positioning the steel bars;

[0026] Step 9: Install the scour detection assembly and the displacement sensor onto the spiral stirrups;

[0027] Step 10: electrically connect the controller to the flushing detection component, the displacement sensor and the wireless transceiver module.

[0028] Step 11: Pour concrete into the pile foundation to complete the construction.

[0029] A disaster early warning method for a bridge anti-scour pile foundation structure comprises the following steps:

[0030] Step A: When the actual scouring depth reaches the designed scouring depth, the pressure sensor is scoured by the river water and feeds back the pressure data to the controller in real time. The controller transmits the pressure data to the command center console through the wireless transceiver module for early warning.

[0031] Step B: When the pile foundation encounters a mountain torrent or mud-rock flow disaster that exceeds the design standard, if the bridge collapses under the action of the excessive lateral impact force, the displacement sensor will feed back the abnormal displacement data to the controller, and the controller will transmit the abnormal displacement data to the command center console through the wireless transceiver module for disaster warning.

[0032] The beneficial effects of the present invention are:

[0033] 1. The manufacturing cost of the scour detection component is low. The scour detection component is directly installed on the upstream water-facing side of the side wall of the pile foundation, which not only simplifies the installation structure of the scour detection component, but also ensures the installation stability and detection accuracy of the scour detection component, avoids the scour detection component from being disturbed by the river water and causing position changes and reduced detection accuracy. It also makes full use of the outer circle of the pile foundation to divert soil, large rocks and other debris carried by the river water, avoiding these debris from gathering at the installation position of the scour detection component, resulting in reduced accuracy of its detection results.

[0034] 2. Within the range from the top of the pile foundation to the designed scour line elevation, a permanent steel plate casing is set on the outside of the pile foundation poured concrete. The steel plate casing is wrapped around the pile foundation poured concrete to resist river scour. This avoids problems such as pile foundation leakage, peeling of pile foundation poured concrete, leakage of pile foundation stress reinforcement, and reduced pile foundation bearing capacity when the bridge pile foundation is subjected to scour, thereby ensuring the safety of the overall bridge structure. From the perspective of the entire life cycle of the bridge, the social impact is small and the economy is good.

[0035] 3. When the actual scouring depth exceeds the designed scouring depth, the pressure sensor is scoured and feeds back the pressure data to the controller. The controller transmits the pressure data to the command center console through the wireless transceiver module for disaster warning. The relevant operation and maintenance units process the warning information in a timely manner to ensure the safety of the bridge structure and the safety of vehicles and pedestrians.

[0036] 4. When the pile foundation encounters a mountain torrent or mud-rock flow disaster that exceeds the design standard, if the bridge collapses under the action of excessive lateral impact force, the displacement sensor will feed back the abnormal displacement data to the controller, and the controller will transmit the abnormal displacement data to the command center console through the wireless transceiver module for disaster warning. The relevant operation and maintenance units will carry out traffic control in time according to the warning information to ensure the safety of people’s lives and property. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1It is a structural schematic diagram of the present invention;

[0038] Figure 2 for Figure 1 Sectional view along Ⅰ-Ⅰ;

[0039] Figure 3 for Figure 1 Cross-sectional view along II-II.

[0040] In the figure: 1-pile foundation cap, 2-pile foundation, 3-top line of construction cofferdam, 4-steel plate casing, 5-positioning steel bars, 6-designed scour line, 8-pile foundation poured concrete, 10-longitudinal force-bearing main bars, 11-strengthening bars, 12-spiral stirrups, 13-displacement sensor, 14-scour detection component. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0042] like Figures 1 to 3 As shown, a bridge anti-scour pile foundation structure described in the present invention includes a pile foundation 2 and a construction cofferdam top surface line 3, a scour detection component 14 is provided on the side wall of the pile foundation 2 on the upstream water-facing side, and the scour detection component 14 is located at the lower side of the designed scour line 6 of the pile foundation 2 and arranged close to the designed scour line 6, and the construction cofferdam top surface line 3 is located above the designed scour line 6. When the actual scour depth reaches the designed scour depth, the scour detection component 14 will be exposed to the water, the scour detection component 14 will be affected by the scouring of the river water, and the scour data will be fed back to the controller in real time, and the controller will transmit the scour data to the command center console through the wireless transceiver module for early warning, and the relevant operation and maintenance units will reinforce or maintain the pile foundation 2 in time according to the early warning information to ensure the safety of the bridge structure and the safety of vehicles and pedestrians. The scour detection component 14 has a low manufacturing cost. The scour detection component 14 is directly installed on the upstream water-facing side of the side wall of the pile foundation 2, which not only simplifies the installation structure of the scour detection component 14, but also ensures the installation stability and detection accuracy of the scour detection component 14, avoids the scour detection component 14 being disturbed by the river water and causing position changes and reduced detection accuracy, and also makes full use of the outer circle of the pile foundation 2 to divert soil, large rocks and other debris carried by the river water, avoiding these debris from gathering at the installation position of the scour detection component 14, resulting in a reduction in the accuracy of its detection results.

[0043] The pile foundation 2 includes a pile foundation cast concrete 8 and a steel skeleton arranged in the pile foundation cast concrete 8, wherein the steel skeleton includes a plurality of longitudinal force-bearing main bars 10, a plurality of reinforcing bars 11 and spiral stirrups 12, wherein the plurality of longitudinal force-bearing main bars 10 are arranged side by side, the plurality of reinforcing bars 11 are connected to all the longitudinal force-bearing main bars 10, and the reinforcing bars 11 are located on the inner side of the area surrounded by all the longitudinal force-bearing main bars 10, and the spiral stirrups 12 are connected to all the longitudinal force-bearing main bars 10 and are located on the outer side of the area surrounded by all the longitudinal force-bearing main bars 10. When in use, the steel bars used in the steel skeleton are hot-rolled steel bars. Since the earth-rock cofferdam is backfilled with loose soil, the pile foundation cast concrete 8 may be consolidated with the surrounding soil and rocks when solidified, and after being washed by water, the local pile foundation cast concrete 8 will be taken away together. After a built bridge has been used for a certain period of time, the underwater bridge pile foundation 2 will experience leakage of the pile foundation, peeling of the pile foundation poured concrete 8, and leakage of the pile foundation stress-bearing steel bars. After the steel bars are exposed and corroded, their bearing capacity is reduced, the pile foundation poured concrete 8 is peeled off, the pile body area is reduced, and the bearing capacity is reduced, affecting the safety of the bridge structure and posing a major safety hazard to vehicles and pedestrians.

[0044] Therefore, the longitudinal main reinforcement 10, reinforcing bars 11, spiral stirrups 12 of the pile foundation 2 bear the load together with the pile foundation cast concrete 8. Multiple longitudinal main reinforcements 10 are welded with the reinforcing bars 11 and spiral stirrups 12 to form a steel skeleton. The longitudinal main reinforcement 10 is at a certain distance from the concrete outer surface of the pile foundation 2. The concrete on the outside of the longitudinal main reinforcement 10 serves as its protective layer, which prevents the longitudinal main reinforcement 10 from being corroded by the external environment during use, thereby ensuring the bearing capacity of the reinforcement, thereby ensuring the safety of the bridge pile foundation structure, and thus ensuring the safety of the bridge structure.

[0045] The scour detection component 14 is a pressure sensor, which is arranged on the spiral stirrup 12 and partially or completely exposed outside the pile foundation cast concrete 8.

[0046] The upper end of the pile foundation 2 is provided with a pile foundation pedestal 1, and a steel plate casing 4 is mounted on the pile foundation 2. The lower end of the steel plate casing 4 extends to the designed scour line 6, and the upper end extends to the top of the construction cofferdam top surface line 3 and is coplanar with the bottom surface of the pile foundation pedestal 1. The pile foundation poured concrete 8 is an underwater concrete material.

[0047] The steel plate casing 4 is coaxially arranged with the steel bar skeleton and is located outside the steel bar skeleton. The steel plate casing 4 is connected with the spiral stirrups 12 through a plurality of positioning steel bars 5 .

[0048] Under flood erosion, the pile foundation 2 of the bridge will cause leakage of the pile foundation, peeling of the poured concrete 8 of the pile foundation, and leakage of the stressed steel bars of the pile foundation, resulting in a reduction in the bearing capacity of the pile foundation, which will cause a major safety hazard to the overall structure of the bridge, affecting the service life of the bridge structure and the appearance of the bridge. During the bridge inspection, after the bridge pile foundation 2 disease is found, it is necessary to interrupt the traffic and transform and reinforce the bridge. The existing solution is mainly to use various methods for reinforcement, such as rust removal of steel bars, then planting steel bars on the pile foundation and filling concrete, etc. The later reinforcement will cause certain damage to the main structure, and the construction is troublesome and the cost is high, causing huge economic losses and social impact.

[0049] To this end, the present invention sets a permanent steel plate casing 4 on the outside of the pile foundation poured concrete 8 within the range of elevation from the top of the pile foundation 2 to the designed scour line 6, and wraps the pile foundation poured concrete 8 through the steel plate casing 4 to resist river scouring, so as to avoid the leakage of the pile foundation, the peeling of the pile foundation poured concrete 8, the leakage of the pile foundation stress steel bars, the reduction of the pile foundation bearing capacity, etc. when the bridge pile foundation 2 is subjected to scouring, thereby ensuring the safety of the overall structure of the bridge. From the perspective of the whole life cycle of the bridge, the social impact is small and the economy is good. The steel plate casing 4 is made of anti-corrosion steel.

[0050] A displacement sensor 13 is provided on the side wall of the pile foundation 2 at the upstream water-facing side. The displacement sensor 13 is located inside the steel plate casing 4 and is arranged close to the upper end of the steel plate casing 4 .

[0051] The displacement sensor 13 is arranged on the spiral stirrup 12 .

[0052] It also includes a controller and a wireless transceiver module. The controller is electrically connected to the flushing detection component 14 and the displacement sensor 13, and the wireless transceiver module is electrically connected to the controller.

[0053] A construction method for a bridge anti-scour pile foundation structure comprises the following steps:

[0054] Step 1: Determine the length and diameter of the pile foundation 2 by calculation based on the survey results.

[0055] Step 2: Complete the flood and sediment characteristics survey and calculate and determine the location of the designed scour line 6.

[0056] Step 3: Determine the top elevation of the construction cofferdam according to the river water level during construction, that is, determine the position of the top line 3 of the construction cofferdam, and then fill the cofferdam to form an underwater construction platform.

[0057] In order to solve the problem that the pile foundation 2 of the bridge may leak out due to scouring during use, the poured concrete 8 of the pile foundation may peel off, the stressed steel bars of the pile foundation may leak out, the bearing capacity of the pile foundation may be reduced, and a major safety hazard may be created for the overall structure of the bridge, thus affecting the service life of the bridge structure, a pile foundation 2 design method is provided to overcome the shortcomings of the existing technology and ensure the safety of bridge use.

[0058] According to the existing bridge design specifications, the design parameters of the pile foundation 2 are mainly determined based on the vertical and lateral loads. The embedding depth of the pile foundation 2 is a key parameter in the calculation. The embedding depth not only directly determines the vertical and lateral bearing capacity of the pile foundation 2 itself, but also affects the calculated length of the pier and the stiffness of the superstructure, and plays a very important role in the overall force calculation of the bridge. The final embedding depth of the pile foundation 2 of the wading bridge is directly related to the scouring depth. The scouring depth of the pile foundation 2 needs to be determined according to the corresponding design standards, taking into account factors such as regional rainfall, water flow velocity, and hydrological sediment characteristics.

[0059] Step 4: According to the coordinates of pile foundation 2, re-position the pile foundation 2 on the construction cofferdam and start the drilling construction of pile foundation 2;

[0060] Step 5: After the drilling is completed, re-measure the hole depth and hole diameter to determine the elevation of the design scour line 6 and the elevation of the top surface line 3 of the construction cofferdam;

[0061] Step 6: Weld the longitudinal main reinforcement 10, the reinforcing reinforcement 11 and the spiral stirrup 12 to form a reinforcement skeleton;

[0062] Step 7: Install the steel bar skeleton section by section in the holes of the pile foundation 2;

[0063] Step 8: Weld and fix the steel plate casing 4 to the steel frame by positioning the steel bars 5;

[0064] Step nine, installing the scour detection assembly 14 and the displacement sensor 13 onto the spiral stirrup 12;

[0065] Step 10: electrically connect the controller to the flushing detection assembly 14, the displacement sensor 13 and the wireless transceiver module.

[0066] Step 11: Pour concrete into the pile foundation 8 to complete the construction.

[0067] A disaster warning method for a bridge anti-scour pile foundation structure comprises the following steps:

[0068] Step A: When the actual scouring depth reaches the designed scouring depth, the pressure sensor is affected by the scouring of the river water and feeds back the pressure data to the controller in real time. The controller transmits the pressure data to the command center console through the wireless transceiver module for early warning.

[0069] During the use of bridges, due to changes in river ditch topography, changes in sediment characteristics, excessive floods caused by excessive rainfall and other reasons, the actual scouring depth of some bridge pile foundations 2 exceeds the designed scouring depth. Due to the large number of bridges in service in my country, the regular inspection time interval is long, and most of these pile foundations 2 are located underwater. It is difficult to find defects in which the scouring depth exceeds the designed scouring depth during the inspection process, which will lead to insufficient vertical and lateral bearing capacity of the pile foundation 2 itself, and at the same time increase the calculated length of the pier, which will cause changes in the mechanical behavior of the overall bridge structure and reduce the ultimate bearing capacity of the overall bridge structure. Under the action of the design ultimate load, the bridge may tilt or collapse, which is very dangerous to the safety of the bridge structure.

[0070] The present invention aims at the scouring problem of pile foundation 2 existing in the use of existing bridges and provides a disaster warning method for pile foundation 2. Specifically, a pressure sensor is provided on the side wall of the pile foundation 2 on the upstream water-facing side, and the pressure sensor is located on the lower side of the designed scouring line 6 of the pile foundation 2 and is arranged close to the designed scouring line 6; when the actual scouring depth exceeds the designed scouring depth, the pressure sensor is scoured and the pressure data is fed back to the controller, and the controller transmits the pressure data to the command center control console through a wireless transceiver module for disaster warning, and the relevant operation and maintenance units process the warning information in time to ensure the safety of the bridge structure and the safety of vehicles and pedestrians.

[0071] Step B: When the pile foundation 2 encounters a mountain torrent or mud-rock flow disaster that exceeds the design standard, if the bridge collapses under the action of the excessive lateral impact force, the displacement sensor 13 will feed back the abnormal displacement data to the controller, and the controller will transmit the abnormal displacement data to the command center console through the wireless transceiver module for disaster warning.

[0072] The mountain gully that the bridge crosses has complex topography and landforms. The gully extends upward for a long distance. The geological conditions of the mountains on both sides of the gully are complex and the catchment area is large. During the rainy season, when the rainfall is large, the gully is prone to flash floods and debris flow disasters. The hydrological and sediment characteristics of flash floods and debris flow are complex and difficult to accurately predict. Flash floods often carry sediment particles, which seriously scour the bridge pile foundation 2. Debris flows often carry large stones and tree trunks, etc., which have a great impact on the bridge pile foundation 2. Once the design standard and bearing capacity are exceeded, the bridge will collapse under the action of the lateral impact force. After the bridge collapses, if there is no timely warning and control, it will cause great harm to the safety of people's lives and property.

[0073] It can be seen that bridges arranged in mountain gullies may collapse under the action of lateral impact force when encountering mountain torrents and debris flow disasters. For this reason, a displacement sensor 13 is provided on the side wall of the pile foundation 2 of the present invention on the upstream water-facing side, and the displacement sensor 13 is located on the inner side of the steel plate casing 4 and arranged close to the upper end of the steel plate casing 4; when the pile foundation 2 encounters a mountain torrent or debris flow disaster exceeding the design standard, under the action of the excessive lateral impact force, if the bridge collapses, the displacement sensor 13 will feed back the abnormal displacement data to the controller, and the controller will transmit the abnormal displacement data to the command center console through the wireless transceiver module for disaster warning, and the relevant operation and maintenance units will carry out traffic control in time according to the warning information to ensure the safety of people's lives and property.

[0074] When a bridge encounters an external force that exceeds the design standard, it will be damaged or collapse, with extremely serious consequences. The present invention takes into account relevant intelligent early warning measures during the design stage, and avoids as much as possible the huge losses to people's lives and property when the bridge encounters extreme natural disasters such as mudslides, thereby increasing the ability to resist disasters. In the bridge design stage, the hidden dangers of damage caused by scouring are eliminated, and the reinforcement and reconstruction of the bridge are avoided to avoid interrupting traffic, further avoiding adverse social impacts and economic losses. The present invention has a simple structure, convenient construction, safety and reliability, and resource conservation, and is conducive to the construction of environmentally friendly bridges. It has significant economic and social benefits and can be widely promoted and applied in the field of bridge technology, especially on bridges that may be subject to mudslide disasters.

Claims

1. A bridge anti-scour pile foundation structure, characterized in that: The invention comprises a pile foundation (2) and a construction cofferdam top surface line (3), wherein a scour detection component (14) is provided on the side wall of the pile foundation (2) on the upstream water-facing side, and the scour detection component (14) is located below a designed scour line (6) of the pile foundation (2) and arranged close to the designed scour line (6), and the construction cofferdam top surface line (3) is located above the designed scour line (6).

2. The bridge anti-scour pile foundation structure according to claim 1, characterized in that: The pile foundation (2) comprises a pile foundation cast concrete (8) and a steel bar skeleton arranged in the pile foundation cast concrete (8), wherein the steel bar skeleton comprises a plurality of longitudinal main force bars (10), a plurality of reinforcing bars (11) and spiral stirrups (12), wherein the plurality of longitudinal main force bars (10) are arranged side by side, the plurality of reinforcing bars (11) are connected to all the longitudinal main force bars (10), and the reinforcing bars (11) are located on the inner side of an area surrounded by all the longitudinal main force bars (10), and the spiral stirrups (12) are connected to all the longitudinal main force bars (10) and are located on the outer side of an area surrounded by all the longitudinal main force bars (10).

3. The bridge anti-scour pile foundation structure according to claim 2, characterized in that: The scour detection component (14) is a pressure sensor, which is arranged on the spiral stirrup (12) and partially or completely exposed outside the pile foundation cast concrete (8).

4. The bridge anti-scour pile foundation structure according to claim 2, characterized in that: A pile foundation pedestal (1) is provided at the upper end of the pile foundation (2), and a steel plate casing (4) is mounted on the pile foundation (2). The lower end of the steel plate casing (4) extends to the designed scour line (6), and the upper end extends to above the top surface line (3) of the construction cofferdam and is coplanar with the bottom surface of the pile foundation pedestal (1).

5. The bridge anti-scour pile foundation structure according to claim 4, characterized in that: The steel plate casing (4) is coaxially arranged with the steel bar skeleton and is located outside the steel bar skeleton. The steel plate casing (4) is connected to the spiral stirrups (12) via a plurality of positioning steel bars (5).

6. The bridge anti-scour pile foundation structure according to claim 4, characterized in that: A displacement sensor (13) is provided on the side wall of the pile foundation (2) on the upstream water-facing side. The displacement sensor (13) is located inside the steel plate casing (4) and is arranged close to the upper end of the steel plate casing (4).

7. The bridge anti-scour pile foundation structure according to claim 6, characterized in that: The displacement sensor (13) is arranged on the spiral stirrup (12).

8. The bridge anti-scour pile foundation structure according to claim 6, characterized in that: It also includes a controller and a wireless transceiver module. The controller is electrically connected to the flushing detection component (14) and the displacement sensor (13), and the wireless transceiver module is electrically connected to the controller.

9. A construction method for a bridge anti-scour pile foundation structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Determine the length and diameter of the pile foundation (2) by calculation based on the survey results; Step 2: Complete the flood and sediment characteristics survey and calculate and determine the location of the designed scour line (6); Step 3: Determine the top elevation of the construction cofferdam according to the river water level during construction, that is, determine the position of the top line (3) of the construction cofferdam, and then fill the cofferdam to form an underwater construction platform; Step 4: According to the coordinates of the pile foundation (2), re-positioning is performed on the construction cofferdam, and the drilling construction of the pile foundation (2) is started; Step 5: After the drilling is completed, the hole depth and hole diameter are re-measured to determine the elevation of the design scour line (6) and the elevation of the top surface line of the construction cofferdam (3); Step 6: welding the longitudinal main reinforcement (10), the reinforcing reinforcement (11) and the spiral stirrup (12) to form a reinforcement skeleton; Step 7: Install the steel reinforcement skeleton section by section in the holes of the pile foundation (2); Step 8: Weld and fix the steel plate casing (4) to the steel frame by positioning the steel bars (5); Step nine, installing the scour detection assembly (14) and the displacement sensor (13) on the spiral stirrup (12); Step 10: electrically connect the controller to the flushing detection assembly (14), the displacement sensor (13) and the wireless transceiver module. Step 11: Pour concrete into the pile foundation (8) to complete the construction.

10. A disaster warning method for a bridge anti-scour pile foundation structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step A: When the actual scouring depth reaches the designed scouring depth, the pressure sensor is scoured by the river water and feeds back the pressure data to the controller in real time. The controller transmits the pressure data to the command center console through the wireless transceiver module for early warning. Step B: When the pile foundation (2) encounters a mountain torrent or debris flow disaster that exceeds the design standard, if the bridge collapses under the action of the excessive lateral impact force, the displacement sensor (13) will feed back abnormal displacement data to the controller, and the controller will transmit the abnormal displacement data to the command center console through the wireless transceiver module for disaster warning.

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