An arch seat foundation for hard rock surface, bridge and construction method

Abstract

The application relates to an arch foundation of an inclined hard rock surface, a bridge and a construction method, and the arch foundation of the inclined hard rock surface comprises a receiving plate and a plurality of steel pipe piles. The receiving plate is cast on the inclined hard rock surface, the top of the receiving plate is connected with a chord, and the chord is perpendicular to the inclined hard rock surface. The plurality of steel pipe piles are perpendicular to the inclined hard rock surface, one end of the plurality of steel pipe piles is obliquely embedded in a rock mass, and the other end of the plurality of steel pipe piles is obliquely embedded in the receiving plate. The plurality of steel pipe piles are obliquely embedded in the rock mass, and the receiving plate is cast on the tail end of the plurality of steel pipe piles to form the arch foundation. The arch foundation construction can be carried out only by opening a hole in the rock mass, large-scale excavation and blasting of the rock mass are avoided, and the technical problems that the foundation structure size of the arch foundation is large in the related art, the excavation volume is large, the supporting difficulty is large, the masonry volume is large, the rock mass is disturbed in the excavation and blasting process, even the slope instability is caused, and the construction safety risk is high are solved.

Description

Technical Field

[0001] This application relates to the field of bridge engineering, specifically to an arch foundation for inclined hard rock surfaces, a bridge, and a construction method. Background Technology

[0002] Currently, in the construction of long-span arch bridges in mountainous areas, the arch abutment foundation, as an important load-bearing component of the arch bridge, transfers the load of the arch bridge to the foundation. Its design and construction quality directly affect the overall safety and economy of the bridge. The arch abutment foundation not only needs to bear large vertical forces, but also large horizontal thrusts, which makes the arch bridge have high requirements for geological conditions.

[0003] In related technologies, arch foundations mainly take the form of open-cut enlarged foundations, composite pile foundations, and inclined and embedded foundations. Constructing arch foundations requires a large amount of excavation and blasting to replace the rock mass with concrete. The foundation structure of arch foundations is relatively large, resulting in a large volume of excavation, difficulty in support, and a large volume of masonry work. During the excavation and blasting process, the rock mass will be disturbed, and even slope instability may be caused, resulting in high construction safety risks.

[0004] Therefore, it is necessary to design a new arch foundation for inclined hard rock surfaces to overcome the above problems. Summary of the Invention

[0005] This application provides an arch foundation for inclined hard rock surfaces, a bridge, and a construction method, which can solve the technical problems in related technologies where the foundation structure of the arch foundation is large in size, resulting in large excavation volume, high support difficulty, large masonry volume, and disturbance of the rock mass during excavation and blasting, and even slope instability, resulting in high construction safety risks.

[0006] In a first aspect, embodiments of this application provide an arch foundation for an inclined hard rock surface, comprising: a support plate and multiple steel pipe piles, wherein the support plate is cast on the inclined hard rock surface, a chord is connected to the top of the support plate, the chord is perpendicular to the inclined hard rock surface; the multiple steel pipe piles are perpendicular to the inclined hard rock surface, and one end of the multiple steel pipe piles is inclinedly embedded in the rock mass, and the other end of the multiple steel pipe piles is inclinedly embedded in the support plate.

[0007] The uniaxial saturated compressive strength of the rock mass is greater than 40 MPa. The bottom surface of the bearing plate is in contact with the inclined hard rock surface. The steel pipe pile is buried in the rock slope. The steel pipe pile extends into the bearing plate and is perpendicular to the inclined hard rock surface. The arch foundation construction can be carried out by simply opening a hole in the rock mass, avoiding large-scale excavation and blasting of the rock mass. Multiple steel pipe piles conform to the natural state of the rock mass, reducing disturbance to the rock mass and lowering the risk of local damage to the rock mass.

[0008] In conjunction with the first aspect, in one embodiment, a plurality of steel pipe piles are arranged around the outer periphery of the chord member, and the spacing between two adjacent steel pipe piles is equal, wherein the ratio of the spacing between two adjacent steel pipe piles to the diameter of the steel pipe pile is set to 2.5 to 3.

[0009] In this example, multiple steel pipe piles are configured as nine steel pipe piles arranged in a square. The multiple steel pipe piles create a group pile effect, improving the anchorage capacity of the arch abutment foundation while reducing the volume of the steel pipe piles and the amount of concrete used. This evenly distributes the arch foot load to a larger area of ​​rock mass, avoiding stress concentration in large-volume foundations. The ratio of the spacing between two adjacent steel pipe piles to the diameter of the steel pipe pile is set to 2.6 to ensure that the stress fields of the multiple steel pipe piles do not overlap, effectively dispersing the load while ensuring the bearing capacity of each arch abutment foundation. The diameter and number of steel pipe piles can be adjusted according to the load requirements of arch bridges with different spans.

[0010] In conjunction with the first aspect, in one embodiment, the steel pipe pile includes a steel pipe in which concrete is poured.

[0011] The outer surface of the steel pipe is set to a rough surface. Exemplarily, the diameter d of the steel pipe pile is set to 300 mm, the wall thickness t of the steel pipe is set to 15 mm, and the strength grade of the concrete is set to C40.

[0012] In conjunction with the first aspect, in one embodiment, the outer surface of the steel pipe is provided with a plurality of interconnected protrusions, the thickness of which is less than or equal to the wall thickness of the steel pipe.

[0013] The protruding strips and the steel pipe form a mechanical connection, enabling a smooth transition between the steel pipe pile and the rock mass, avoiding stress concentration caused by abrupt changes in the cross-section, and ensuring that the stress is evenly distributed across the entire cross-section when the steel pipe is under load. The spacing between two adjacent protruding strips is equal. The protruding strips increase the anchoring force and friction between the steel pipe pile and the rock mass, avoiding large-scale excavation and support around the steel pipe, reducing construction difficulty. At the same time, the protruding strips form a continuous protective layer to prevent surface corrosion of the steel pipe and extend the service life of the steel pipe pile.

[0014] In conjunction with the first aspect, in one embodiment, the convex strip is configured as an annular shape.

[0015] The convex strip can adapt to the changes in the components of the arch bridge thrust in different directions, resisting both axial pressure and pull-out force. For rock masses with uneven joint development, the convex strip ensures that the steel pipe pile has sufficient anchoring force in any direction, while improving the uniformity of contact stress and reducing the risk of local rock mass failure.

[0016] In conjunction with the first aspect, in one embodiment, the cross-section of the receiving plate is set to be rectangular, and the ratio of the thickness of the receiving plate to the diameter of the steel pipe pile is greater than 3.

[0017] The top surface area of ​​the receiving plate is smaller than the bottom surface area to reduce the volume of the receiving plate while ensuring the connection strength between the receiving plate and the steel pipe pile. The transverse width of the receiving plate is set to B1, the longitudinal width of the receiving plate is set to B2, the transverse net moment of the steel pipe pile is set to s1, the longitudinal net moment of the steel pipe pile is set to s2, and the net edge distance of the steel pipe pile is set to b. Exemplarily, the ratio of the thickness H of the receiving plate to the diameter d of the steel pipe pile is set to 6.

[0018] In conjunction with the first aspect, in one embodiment, the diameter of the steel pipe pile is set to 200~600 mm.

[0019] In this example, the length L of the steel pipe pile in the rock mass is set to 10m, the length of the steel pipe pile in the bearing plate is set to 270cm, and the diameter of the steel pipe pile is set to 260mm. This fully utilizes the strength of the rock mass, ensuring that the anchoring force of the arch foundation is not insufficient due to the diameter of the steel pipe pile being too small, nor that the arch foundation exceeds the local bearing capacity of the rock mass due to the diameter of the steel pipe pile being too large. This guarantees the bearing capacity of the steel pipe pile while reducing the amount of material used for the steel pipe pile and the amount of excavation work.

[0020] In conjunction with the first aspect, in one embodiment, the angle between the inclined hard rock surface and the ground is set to be greater than 45°.

[0021] Wherein, when the angle between the inclined hard rock surface and the ground... When the angle is set to greater than 45°, the bearing capacity of the arch foundation is stronger than that of the large pile foundation, the corresponding excavation volume is reduced, the excavation difficulty is reduced, and the damage to the slope and the surrounding environment is less.

[0022] Secondly, embodiments of this application provide a bridge comprising at least two arch foundations and a steel truss arch. The steel truss arch is installed on at least two of the arch foundations. Each arch foundation includes a support plate and multiple steel pipe piles. The support plate is cast into an inclined hard rock surface. A chord is connected to the top of the support plate, and the chord is perpendicular to the inclined hard rock surface. The multiple steel pipe piles are perpendicular to the inclined hard rock surface, and one end of each steel pipe pile is inclinedly embedded in the rock mass, while the other end of each steel pipe pile is inclinedly embedded in the support plate.

[0023] In this example, at least two of the arch foundations are configured as four arch foundations, located at the four corners of the steel truss arch. The load of the steel truss arch is directly transferred to the depth of the rock mass through the arch foundations. The bottom surface of the bearing plate is in contact with the inclined hard rock surface. The steel pipe piles are embedded in the rock slope, with part of the steel pipe piles extending into the bearing plate. The steel pipe piles are perpendicular to the inclined hard rock surface. The arch foundation construction can be carried out by simply opening a hole in the rock mass, avoiding large-scale excavation and blasting of the rock mass.

[0024] Thirdly, embodiments of this application provide a construction method for an arch foundation on an inclined hard rock surface, characterized in that... Clear the sloping hard rock surface and excavate the opening for steel pipe piles; A steel pipe pile is inserted into the hole of the steel pipe pile, and concrete is poured into the pile body. A bearing plate is poured on the steel pipe pile, and chord members are constructed on the upper inclined surface of the bearing plate to form an arch foundation.

[0025] The process involves first clearing the sloping, hard rock surface to expose the rock mass. Then, drilling holes with equal cross-sections along the pile axis within the rock mass to form the steel pipe pile opening. Next, placing a steel pipe inside the opening and pouring concrete into it, then injecting cement grout between the steel pipe and the hole wall of the steel pipe pile opening and filling it. Finally, pouring concrete at the tail end of the steel pipe pile to form a support plate, with the steel pipe pile connected to the support plate. Finally, constructing a chord on the upper inclined surface of the support plate to form an arch foundation.

[0026] The beneficial effects of the technical solutions provided in this application include: By embedding multiple steel pipe piles at an incline within the rock mass and covering the ends of these piles with cast-in-place plates, an arch foundation is formed. The steel pipe piles are perpendicular to the inclined hard rock surface, the cast-in-place plates are cast onto the surface, and chord members are cast on top of the plates. This method allows for arch foundation construction simply by creating openings within the rock mass, avoiding large-scale excavation and blasting. It solves the technical problems associated with arch foundations in related technologies, such as large foundation structure dimensions leading to large excavation volumes, difficult support, and large masonry volumes, as well as the potential for rock mass disturbance and slope instability during excavation and blasting, resulting in high construction safety risks. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1A side view of an arch foundation for an inclined hard rock surface provided for an embodiment of this application; Figure 2 A schematic diagram of the arch foundation provided in an embodiment of this application; Figure 3 for Figure 2 Sectional view of AA; Figure 4 A side view of a steel pipe pile provided in an embodiment of this application; Figure 5 A top view of a steel pipe pile provided in an embodiment of this application; Figure 6 A cross-sectional view of a steel pipe pile provided in an embodiment of this application; Figure 7 This is a structural schematic diagram of the arch foundation and steel truss arch provided in the embodiments of this application.

[0029] In the diagram: 1. Support plate; 2. Inclined hard rock surface; 3. Chord member; 4. Steel pipe pile; 41. Steel pipe; 42. Concrete; 43. Raised bar; 100. Arch foundation; 200. Steel truss arch. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0031] This application provides an arch foundation, bridge, and construction method for inclined hard rock surfaces. It can solve the technical problems of large foundation structure size of arch foundation, resulting in large excavation volume, high support difficulty, large masonry volume, disturbance of rock mass during excavation and blasting, and even slope instability, resulting in high construction safety risks.

[0032] See Figure 1-3 As shown in the embodiment of this application, an arch foundation for an inclined hard rock surface is provided, which includes: a support plate 1 and multiple steel pipe piles 4. The support plate 1 is cast on the inclined hard rock surface 2, and a chord 3 is connected to the top of the support plate 1. The chord 3 is perpendicular to the inclined hard rock surface 2. The multiple steel pipe piles 4 are perpendicular to the inclined hard rock surface 2, and one end of the multiple steel pipe piles 4 is inclinedly embedded in the rock mass, and the other end of the multiple steel pipe piles 4 is inclinedly embedded in the support plate 1.

[0033] In this embodiment, the uniaxial saturated compressive strength of the rock mass is greater than 40 MPa. The bottom surface of the bearing plate 1 is in contact with the inclined hard rock surface 2. The steel pipe pile 4 is buried in the rock slope. The steel pipe pile 4 extends into the bearing plate 1 and is perpendicular to the inclined hard rock surface 2. The arch foundation 100 can be constructed simply by opening a hole in the rock mass, avoiding large-scale excavation and blasting of the rock mass. The multiple steel pipe piles 4 conform to the natural state of the rock mass, reducing disturbance to the rock mass and lowering the risk of local damage to the rock mass.

[0034] The arch foundation 100 is located at the arch foot node of the steel truss arch bridge. The arch foundation 100 directly bears the load reaction force at the arch foot and transmits it to the rock mass. The load reaction force includes pressure N, bending moment M, and shear force F. The direction of pressure N is set to be perpendicular to the inclined hard rock surface 2, and the direction of shear force F is set to be parallel to the inclined hard rock surface 2. Pressure N and bending moment M are converted into axial force of steel pipe pile 4. When the steel pipe pile 4 is compressed, the frictional force between the pipe wall of the steel pipe pile 4 and the rock mass, as well as the frictional force between the bottom surface of the steel pipe pile 4 and the rock mass, are also affected. The contact surface pressures work together to resist the pressure. When the steel pipe pile 4 is under tension, the friction between the steel pipe pile wall and the rock mass resists the tension. The shear force is resisted by the friction between the bearing plate 1 and the inclined hard rock surface 2. For example, taking a steel truss arch bridge with a main span of 300m as an example, the arch foundation 100 is located in the rock mass with a basic bearing capacity of 1000kPa. The concrete volume of the arch foundation 100 is 500 cubic meters, and the concrete volume of the steel pipe pile 4 is 280 cubic meters, which reduces the masonry volume of the foundation by about 6000 cubic meters.

[0035] This embodiment forms an arch foundation 100 by embedding multiple steel pipe piles 4 at an incline within the rock mass and covering the tail ends of the steel pipe piles 4 with a cast-in-place support plate 1. The multiple steel pipe piles 4 are perpendicular to the inclined hard rock surface 2, the support plate 1 is cast on the inclined hard rock surface 2, and the chord member 3 is cast on top of the support plate 1. The arch foundation 100 can be constructed simply by opening a hole in the rock mass, avoiding large-scale excavation and blasting of the rock mass. This solves the technical problems in related technologies where the foundation structure of the arch foundation 100 has a large foundation size, resulting in large excavation volume, high support difficulty, large masonry volume, and disturbance of the rock mass during excavation and blasting, which may even cause slope instability and high construction safety risks.

[0036] Further, see Figure 1-3 As shown, in some embodiments, multiple steel pipe piles 4 are arranged around the outer periphery of the chord 3, and the spacing between two adjacent steel pipe piles 4 is equal, and the ratio of the spacing between two adjacent steel pipe piles 4 to the diameter of the steel pipe pile 4 is set to 2.5~3.

[0037] In this embodiment, exemplary, the multiple steel pipe piles 4 are configured as nine steel pipe piles 4 arranged in a square. The multiple steel pipe piles 4 create a group pile effect, improving the anchorage capacity of the arch foundation 100, while reducing the volume of the steel pipe piles 4 and the amount of concrete used. This evenly distributes the arch foot load over a larger area of ​​rock, avoiding stress concentration in large-volume foundations. The ratio of the spacing between two adjacent steel pipe piles 4 to the diameter of the steel pipe pile 4 is set to 2.6 to ensure that the stress fields of the multiple steel pipe piles 4 do not overlap, effectively dispersing the load while ensuring the bearing capacity of each arch foundation 100. The diameter and number of steel pipe piles 4 can be adjusted according to the load requirements of arch bridges with different spans. In other embodiments, multiple steel pipe piles 4 are arranged in a circle.

[0038] Further, see Figure 4-6 As shown, in some embodiments, the steel pipe pile 4 includes a steel pipe 41, and concrete 42 is poured inside the steel pipe 41.

[0039] In this embodiment, the outer surface of the steel pipe 41 is set to a rough surface. Exemplarily, the diameter d of the steel pipe pile 4 is set to 300 mm, the wall thickness t of the steel pipe 41 is set to 15 mm, and the strength grade of the concrete 42 is set to C40.

[0040] Further, see Figure 4-6 As shown, in some embodiments, the outer surface of the steel pipe 41 is provided with a plurality of interconnected protrusions 43, the thickness of the protrusions 43 being less than or equal to the wall thickness of the steel pipe 41.

[0041] In this embodiment, the protrusion 43 and the steel pipe 41 form a mechanical connection, realizing a smooth transition between the steel pipe pile 4 and the rock mass, avoiding stress concentration caused by abrupt changes in the cross section, and ensuring that the stress of the steel pipe 41 can be evenly distributed throughout the cross section when bearing load. The spacing between two adjacent protrusions 43 is equal. The protrusion 43 increases the anchoring force and friction between the steel pipe pile 4 and the rock mass, avoiding large-scale excavation and support on the outer periphery of the steel pipe 41, reducing construction difficulty. At the same time, the protrusion 43 forms a continuous protective layer to prevent surface corrosion of the steel pipe 41 and extend the service life of the steel pipe pile 4.

[0042] Further, see Figure 4-6 As shown, in some embodiments, the protrusion 43 is configured as an annular shape.

[0043] In this embodiment, the protrusion 43 can adapt to the component changes of the arch bridge thrust in different directions, resisting both axial pressure and pull-out force. For rock masses with uneven joint development, the protrusion 43 ensures that the steel pipe pile 4 has sufficient anchoring force in any direction, while improving the uniformity of contact stress and reducing the risk of local rock mass failure.

[0044] Further, see Figure 1-3 As shown, in some embodiments, the cross-section of the receiving plate 1 is set to rectangular, and the ratio of the thickness of the receiving plate 1 to the diameter of the steel pipe pile 4 is greater than 3.

[0045] In this embodiment, the top surface area of ​​the receiving plate 1 is smaller than the bottom surface area of ​​the receiving plate 1, reducing the volume of the receiving plate 1 while ensuring the connection strength between the receiving plate 1 and the steel pipe pile 4. The transverse width of the receiving plate 1 is set to B1, the longitudinal width of the receiving plate 1 is set to B2, the transverse net moment of the steel pipe pile 4 is set to s1, the longitudinal net moment of the steel pipe pile 4 is set to s2, and the net edge distance of the steel pipe pile 4 is set to b. Exemplarily, the ratio of the thickness H of the receiving plate 1 to the diameter d of the steel pipe pile 4 is set to 6. In other embodiments, the cross-section of the receiving plate 1 is set to circular or square.

[0046] Further, see Figure 2-4 As shown, in some embodiments, the diameter of the steel pipe pile 4 is set to 200~600 mm.

[0047] In this embodiment, exemplary, the length L of the steel pipe pile 4 located in the rock mass is set to 10m, the length of the steel pipe pile 4 located in the bearing plate 1 is set to 270cm, and the diameter of the steel pipe pile 4 is set to 260mm. This fully utilizes the strength of the rock mass, ensuring that the anchoring force of the arch foundation 100 is not insufficient due to the diameter of the steel pipe pile 4 being too small, nor that the arch foundation 100 exceeds the local bearing capacity of the rock mass due to the diameter of the steel pipe pile 4 being too large. This guarantees the bearing capacity of the steel pipe pile 4 while reducing the material usage of the steel pipe pile 4 and the amount of excavation work.

[0048] Further, see Figure 1 As shown, in some embodiments, the angle between the inclined hard rock surface 2 and the ground is set to be greater than 45°.

[0049] In this embodiment, when the angle between the inclined hard rock surface 2 and the ground... When the angle is set to greater than 45°, the arch foundation 100 has a stronger bearing capacity than the arch foundation of the large pile foundation, the corresponding excavation volume is reduced, the excavation difficulty is reduced, and the damage to the slope and the surrounding environment is less.

[0050] See Figure 7As shown in the figure, this application provides a bridge comprising at least two arch foundations 100 and a steel truss arch 200. The steel truss arch 200 is installed on the at least two arch foundations 100. Each arch foundation 100 includes a support plate 1 and multiple steel pipe piles 4. The support plate 1 is cast into an inclined hard rock surface 2. A chord 3 is connected to the top of the support plate 1, and the chord 3 is perpendicular to the inclined hard rock surface 2. The multiple steel pipe piles 4 are perpendicular to the inclined hard rock surface 2, and one end of the multiple steel pipe piles 4 is inclinedly embedded in the rock mass, while the other end of the multiple steel pipe piles 4 is inclinedly embedded in the support plate 1.

[0051] In this embodiment, at least two of the arch foundations 100 are provided as four arch foundations 100. The arch foundations 100 are located at the four corners of the steel truss arch 200. The load of the steel truss arch 200 is directly transferred to the depth of the rock mass through the arch foundations 100. The bottom surface of the bearing plate 1 is in contact with the inclined hard rock surface 2. The steel pipe pile 4 is buried in the rock slope. The steel pipe pile 4 extends into the bearing plate 1 and is perpendicular to the inclined hard rock surface 2. The construction of the arch foundation 100 can be carried out by simply opening a hole in the rock mass, avoiding large-scale excavation and blasting of the rock mass.

[0052] No. Axial force of steel pipe pile 4 Satisfy the following formula: In the formula The number of steel pipe piles 4. For the first The distance from the center of the bearing plate to the fourth steel pipe pile, and the allowable bearing capacity of the steel pipe pile satisfy the following formula: ,in In the formula The allowable bearing capacity of steel pipe piles, It is the uniaxial saturated compressive strength. The borehole circumference of steel pipe pile 4 embedded in the rock strata. The embedment depth of steel pipe pile 4. The coefficient is determined based on the degree of rock fragmentation. Based on the coefficients determined according to the rock strata clearing conditions, the required length of steel pipe pile 4 and the maximum compressive stress of steel pipe pile 4 are determined. Satisfy the following formula: , This represents the maximum axial compressive force of steel pipe pile 4. Given the diameter of steel pipe pile 4, the allowable compressive strength of concrete considering the hoop effect. Satisfy the following formula: Considering only the stress on the steel pipe, the maximum tensile stress of steel pipe pile 4 is... Satisfy the following formula: , This represents the maximum axial tensile force of steel pipe pile 4. t is the diameter of steel pipe pile 4, t is the wall thickness of steel pipe 41, and t is the allowable tensile strength of the steel pipe. Satisfy the following formula: .

[0053] Taking a 400m span steel truss arch bridge in a mountainous area as an example, the rock slope is a hard granite slope with a uniaxial saturated compressive strength of... The angle between the slope surface and the ground is set to 50°, and the load reaction at a single arch foot node is as follows: , , The number of steel pipe piles 4 The diameter of steel pipe pile 4 The wall thickness of steel pipe 41 The spacing between adjacent steel pipe piles 4 is 1500 mm, the spacing between adjacent convex strips 43 is 200 mm, the steel pipe 41 is made of Q345 steel, the concrete 42 is made of C40 strength grade concrete, and the transverse width of the bearing plate 1 is... The longitudinal width of the receiving plate 1 The steel pipe pile 4 is embedded 10.0m into the rock mass of the rock slope, and the length of the steel pipe pile 4 extending into the bearing plate 1 is 1.5m. The maximum axial pressure of the steel pipe pile 4 is... When shaftless tension appears, take , The allowable bearing capacity of steel pipe piles in a single-pile foundation was calculated. ,satisfy The maximum compressive stress of steel pipe pile 4 Allowable compressive strength of concrete considering the hoop effect ,satisfy In this application, the arch foot load reaction force is precisely transferred to the rock slope through the bearing plate 1 and the steel pipe pile 4, without stress concentration. The structure is safe and stable under stress. Compared with the open-cut enlarged foundation of the same span, the excavation volume is reduced by about 90%, there is no blasting operation, the concrete masonry volume is reduced by about 95%, the construction period is shortened by about 40%, and the project cost is reduced by 65%. Only a small amount of cleaning is required on the slope surface during the entire construction process. There is no need for large-scale mountain excavation, and the damage to the mountain ecological environment is minimized, which meets the requirements of green engineering.

[0054] This application provides a construction method for an arch foundation on an inclined hard rock surface, characterized in that... Step 1: Clear the sloping hard rock surface 2 and excavate the steel pipe pile hole.

[0055] Step 2: Insert steel pipe pile 4 into the hole of steel pipe pile and pour concrete into the pile body of steel pipe pile 4.

[0056] Step 3: Cast the bearing plate 1 on the steel pipe pile 4, and construct the chord 3 on the upper inclined surface of the bearing plate 1 to form the arch foundation 100.

[0057] In this embodiment, the inclined hard rock surface 2 is first cleared to expose the rock surface. Holes with equal cross sections along the pile axis are drilled sequentially in the rock body to form the steel pipe pile opening. Then, a steel pipe 41 is placed in the steel pipe pile opening, and concrete 42 is poured into the steel pipe 41. Cement grout is injected and filled between the steel pipe 41 and the hole wall of the steel pipe pile opening. Then, concrete 42 is poured at the tail end of the steel pipe pile 4 to form a support plate 1, wherein the steel pipe pile 4 is connected to the support plate 1. Finally, a chord 3 is constructed on the upper inclined surface of the support plate 1 to form an arch foundation 100.

[0058] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0059] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An arch foundation for an inclined hard rock surface, characterized in that, It includes: A support plate (1) is cast on an inclined hard rock surface (2). A chord (3) is connected to the top of the support plate (1). The chord (3) is perpendicular to the inclined hard rock surface (2). Multiple steel pipe piles (4) are perpendicular to the inclined hard rock surface (2), and one end of the multiple steel pipe piles (4) is inclinedly embedded in the rock body, and the other end of the multiple steel pipe piles (4) is inclinedly embedded in the bearing plate (1).

2. The arch foundation as described in claim 1, characterized in that, Multiple steel pipe piles (4) are arranged around the outer periphery of the chord (3), and the distance between two adjacent steel pipe piles (4) is equal. The ratio of the distance between two adjacent steel pipe piles (4) to the diameter of the steel pipe pile (4) is set to 2.5~3.

3. The arch foundation as described in claim 1, characterized in that, The steel pipe pile (4) includes a steel pipe (41) and concrete (42) is poured inside the steel pipe (41).

4. The arch foundation as described in claim 3, characterized in that, The outer surface of the steel pipe (41) is provided with a plurality of interconnected protrusions (43), the thickness of which is less than or equal to the wall thickness of the steel pipe (41).

5. The arch foundation as described in claim 4, characterized in that, The protrusion (43) is configured as a ring.

6. The arch foundation as described in claim 1, characterized in that, The cross-section of the receiving plate (1) is rectangular, and the ratio of the thickness of the receiving plate (1) to the diameter of the steel pipe pile (4) is greater than 3.

7. The arch foundation as described in claim 1, characterized in that, The diameter of the steel pipe pile (4) is set to 200~600 mm.

8. The arch foundation as described in claim 1, characterized in that, The angle between the inclined hard rock surface (2) and the ground is set to be greater than 45°.

9. A bridge, characterized in that, It includes at least two arch foundations (100) and a steel truss arch (200), the steel truss arch (200) being installed on at least two of the arch foundations (100), the arch foundations (100) including a support plate (1) and multiple steel pipe piles (4), the support plate (1) being cast on an inclined hard rock surface (2), the top of the support plate (1) being connected to a chord (3), the chord (3) being perpendicular to the inclined hard rock surface (2); the multiple steel pipe piles (4) being perpendicular to the inclined hard rock surface (2), and one end of the multiple steel pipe piles (4) being inclinedly embedded in the rock body, and the other end of the multiple steel pipe piles (4) being inclinedly embedded in the support plate (1).

10. A construction method for an arch foundation on an inclined hard rock surface as described in claim 1, characterized in that, Clear the sloping hard rock surface (2) and excavate the steel pipe pile hole; Insert steel pipe piles (4) into the opening of the steel pipe pile hole and pour concrete into the pile body of the steel pipe piles (4); A bearing plate (1) is poured on the steel pipe pile (4), and a chord member (3) is constructed on the upper inclined surface of the bearing plate (1) to form an arch foundation (100).

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