A reverse circulation construction device for bored piles of bridges

Abstract

The present application relates to a reverse circulation construction device for bored cast-in-place piles for bridges, belonging to the field of bridges, which includes a foundation pit casing, the foundation pit casing being coaxially embedded at the orifice of the pile hole, a grouting drill rod being coaxially penetrated in the pile hole, a mud pool being opened on the ground next to the pile hole, a drainage pipe being fixedly connected to the foundation pit casing, one end of the drainage pipe being connected to the mud pool, and the other end being connected to the inner cavity of the foundation pit casing and the pile hole, a drainage mechanism being provided on the foundation pit casing, the drainage mechanism being used to cause mud to rush from the foundation pit casing to the grouting drill rod, and a water pump being provided on the drainage pipe. The present application causes the mud entering the pile hole to rush to the grouting drill rod, and the grouting drill rod can then serve as a drainage rod to guide the mud down. During the descent process, the mud has a low scouring force on the inner wall of the pile hole, which reduces the probability of soil collapse of the hole wall to a certain extent.

Description

Technical Field

[0001] The present application relates to the field of bridge construction, and in particular to a reverse circulation construction device for bored cast-in-place piles of bridges. Background Art

[0002] The bridge pile head, also known as the bridge pile foundation, is the part where the bridge substructure contacts the foundation. It bears all the loads from the bridge superstructure and transfers them and the substructure loads to the foundation to ensure the safety and normal use of the entire bridge.

[0003] In related technology, bridge pile foundations are bored concrete piles. Bored concrete piles are created on-site by mechanical drilling, steel pipe extrusion, or manual excavation. A steel cage is placed inside the pile hole and then poured with concrete. Sedimentation tanks are connected to the foundation pit surface and located next to the pile hole. These tanks hold slurry. The bored pile process is divided into two types: positive-circulation rotary drilling and reverse-circulation rotary drilling, depending on the slag removal method.

[0004] Reverse circulation rotary drilling uses the drilling rig's rotary device to drive the drill rod and drill bit to rotate and cut and crush the rock and soil. The circulating wall protection mud is sucked by pump suction, air lift, injection and other measures, and the drill cuttings are sucked out of the hole from the inner cavity of the drill rod and flow into the sedimentation tank. After sedimentation and filtration, it flows back into the pile hole again.

[0005] In reverse circulation rotary drilling, the hole cleaning mud continuously flows downward from between the drill rod and the pile hole wall, which has a continuous scouring effect on the soil of the pile hole wall and exerts a continuous force on it. The risk of hole wall collapse is greater than that of positive circulation rotary drilling. Summary of the Invention

[0006] In order to improve the above problems, the present application provides a reverse circulation construction device for bored cast-in-place piles of bridges.

[0007] The present application provides a bridge bored pile reverse circulation construction device that adopts the following technical solution:

[0008] A reverse circulation construction device for bored cast-in-place piles for bridges comprises a foundation pit casing, which is coaxially embedded in the mouth of the pile hole, a grouting drill rod is coaxially passed through the pile hole, a mud pool is provided on the ground next to the pile hole, a drainage pipe is fixedly connected to the foundation pit casing, one end of the drainage pipe is connected to the mud pool, and the other end is connected to the inner cavity of the foundation pit casing and the pile hole, a drainage mechanism is provided on the foundation pit casing, and the drainage mechanism is used to make the mud rush from the foundation pit casing to the grouting drill rod, and a water pump is provided on the drainage pipe.

[0009] By adopting the above technical solution, the mud entering the pile hole rushes towards the grouting drill rod, and then the grouting drill rod can be used as a drainage rod to guide the mud to descend. During the descent, the scouring force of the mud on the inner wall of the pile hole is relatively low, which reduces the probability of soil collapse of the hole wall to a certain extent.

[0010] Preferably, the foundation pit casing includes an outer cylinder and an inner cylinder which are coaxially fixedly connected to each other, a drainage gap is formed between the outer cylinder and the inner cylinder, a plurality of drainage holes are opened on the inner cylinder, and the plurality of drainage holes are arranged in a circular array with the axis of the foundation pit casing as the center, and the drainage mechanism includes a drainage plate, which is located on the side of the inner cylinder facing the grouting drill rod, and the drainage plate is located below the drainage hole.

[0011] Preferably, the guide plate is hinged to the inner cylinder, and the hinge axis of the two is located below the drainage hole. A torsion spring is provided on the hinge axis of the guide plate and the inner cylinder, and the torsion spring applies a torsional force to flip the guide plate upward.

[0012] By adopting the above technical solution, after the mud is ejected from the drainage hole, the drainage plate further guides the mud flow, reducing the probability of the mud contacting the inner wall of the pile hole. Under the action of the torsion spring, a certain pressure is required for the mud to rush out of the drainage hole, which increases the pressure of the liquid that successfully enters the pile hole and further reduces the probability of the mud flowing down along the inner wall of the pile hole.

[0013] Preferably, a seam membrane is fixedly connected between adjacent drainage plates, the seam membrane is an elastic geomembrane, and a receiving groove for the seam membrane is provided on the side edge of the drainage plate.

[0014] By adopting the above technical solution, during the flipping process of the guide plates, the adjacent guide plates are always connected and the gaps are sealed by the seam membrane, which reduces the probability of mud seeping out from there and also improves the synchronization of the working process of each guide plate.

[0015] Preferably, the axis of the drainage pipe is parallel to the horizontal direction, and the projection of the axis of the drainage pipe in the axial direction of the pile hole is the tangent of the outer wall of the inner tube. The drainage mechanism also includes a slurry component, which is used to improve the uniformity of the distribution of mud in the circumferential direction of the foundation pit casing when it flows to the drainage hole.

[0016] By adopting the above technical solution, when the mud enters the drainage gap, the mud rotates in the drainage gap under the guidance of the outer wall of the inner tube and the inner wall of the outer tube, thereby increasing the filling degree of the mud in the drainage gap.

[0017] Preferably, the slurry assembly includes a flow balancing rotor, which is coaxially connected to the foundation pit casing, and the flow balancing rotor includes a flow balancing ring plate and a plurality of power sailboards. The flow balancing ring plate is located in the drainage gap and is coaxial with the foundation pit casing, and the plurality of power sailboards are arranged in a ring array and fixedly connected to the flow balancing ring plate. The projection of the drainage pipe in the horizontal direction is located within the height range of the power sailboard, and the flow balancing ring plate is provided with a plurality of slurry holes that pass through its own thickness.

[0018] By adopting the above technical solution, the impact force generated when the mud fluid rushes into the drainage gap can act as thrust on the power sailboard, driving the flow-equalizing rotor to rotate in a directional manner. At the same time, the mud between the pressure control ring plate and the flow-equalizing ring plate can continue to flow downward through the slurry hole. The rotating flow-equalizing rotor can improve the uniform speed of the mud at different angles and directions when it rotates in the drainage gap.

[0019] Preferably, the surface of the power sailboard is perpendicular to the surface of the flow equalizing ring plate, and each of the power sailboards is fixedly connected to the same pressure control ring plate on the side away from the flow equalizing ring plate. The shape of the pressure control ring plate is consistent with that of the flow equalizing ring plate, and each of the power sailboards is provided with a pressure equalizing hole.

[0020] By adopting the above technical solution, due to the presence of the equalizing holes, the hydraulic pressure between each power sailboard can be made equal when the mud injection power is continuously increased, and the flow distribution along the circumference of the equalizing rotor is also more balanced when the mud penetrates downward.

[0021] Preferably, a speed regulating hole is opened on the flow balancing ring plate, and a speed regulating plate is movably connected to the flow balancing ring plate at the speed regulating hole. The plate surface of the speed regulating plate is in contact with the plate surface of the flow balancing ring plate. The speed regulating plate moves to control the closing or opening of the speed regulating hole. The homogenizing assembly also includes a control part for controlling the movement of the speed regulating plate.

[0022] Preferably, the speed regulating plate is slidingly connected to the current balancing ring plate, and the sliding direction is the radial direction of the current balancing ring plate. The control member is a centrifugal spring, and the expansion and contraction direction of the centrifugal spring is the radial direction of the current balancing ring plate. One end of the centrifugal spring is fixedly connected to the current balancing ring plate, and the other end is fixedly connected to the speed regulating plate.

[0023] By adopting the above technical solution, when the mud flow rate needs to be increased, the power of the water pump is increased, the fluid pressure is increased, and the speed of the flow-equalizing rotor is increased. Under the action of centrifugal force, the speed regulating plate tends to move away from the inner cylinder, the centrifugal spring is compressed, and the speed regulating hole is opened. The higher the speed, the greater the degree to which the speed regulating hole is opened, and the higher the rate at which the mud passes through the flow-equalizing ring plate.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. Through the setting of the drainage mechanism, the mud after entering the pile hole rushes to the slurry extraction drill rod, and then the slurry extraction drill rod can serve as a drainage rod to guide the mud down. During the descent process, the scouring force of the mud on the inner wall of the pile hole is relatively low, which reduces the probability of soil collapse of the hole wall to a certain extent;

[0026] 2. Through the setting of the equalizing component, the equalizing rotor rotates continuously during the impact of the mud. The existence of the equalizing holes makes the hydraulic pressure between each power sailboard tend to be equal, that is, the mud volume distribution in the circumferential direction of the drainage gap is more even, and then the mud seeps downward through the equalizing ring plate and reaches the drainage holes. The mud volume and flow rate ejected from each drainage hole also tend to be equal, so the mud flow into the pile hole is also more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic cross-sectional view of the construction structure of the reverse circulation construction device for bored cast-in-place piles for bridges in an embodiment of the present application.

[0028] Figure 2 It is a structural diagram used to reflect the drainage mechanism in the embodiment of the present application.

[0029] Figure 3 It is a structural diagram used to reflect the flow-balancing rotor in an embodiment of the present application.

[0030] Figure 4 It is a structural schematic diagram used to illustrate the lifting of the guide plate in the embodiment of the present application.

[0031] Figure 5 It is a structural diagram used to illustrate the situation in which all the drainage plates are flushed open in an embodiment of the present application.

[0032] Explanation of the accompanying reference numerals: 1. Pile hole; 11. Mud pool; 12. Slurry extraction drill rod; 2. Foundation pit casing; 21. Outer tube; 22. Inner tube; 221. Drainage hole; 23. Drainage pipe; 231. Water pump; 3. Drainage mechanism; 31. Drainage plate; 311. Receiving tank; 32. Joint membrane; 4. Slurry assembly; 41. Flow balancing rotor; 411. Flow balancing ring plate; 412. Pressure control ring plate; 413. Power sailboard; 414. Pressure balancing hole; 415. Slurry hole; 416. Speed ​​regulating hole; 42. Speed ​​regulating plate; 43. Centrifugal spring. DETAILED DESCRIPTION

[0033] The following is combined with Figure 1-5 This application is described in further detail.

[0034] The present application discloses a reverse circulation construction device for bored piles of bridges. Figure 1As shown, it includes a foundation pit casing 2 and a drainage mechanism 3. A vertical pile hole 1 is opened on the ground, and a mud pool 11 is dug next to the pile hole 1. The mud pool 11 is connected to the pile hole 1 and contains mud for cleaning the pile hole 1. A grouting drill rod 12 is coaxially passed through the pile hole 1. The lower end of the grouting drill rod 12 is connected to a drill bit for rotary drilling (not shown in the figure). During the drilling and cleaning process, the grouting drill rod 12 continuously sucks the mud at the bottom of the pile hole 1 to the outside; the foundation pit casing 2 is embedded in the pile hole 1 and is located at the hole mouth. The drainage mechanism 3 is used to allow the mud to flow from the mud pool 11 through the foundation pit casing 2 and rush to the grouting drill rod 12.

[0035] like Figure 1 and 2 As shown, the foundation pit casing 2 comprises an outer tube 21 and an inner tube 22, which are coaxially fixedly connected. The inner wall of the inner tube 22 is flush with the wall of the pile hole 1, and an annular drainage gap is formed between the outer tube 21 and the inner tube 22. A drainage pipe 23 is fixedly connected to the outer wall of the outer tube 21. One end of the drainage pipe 23 is connected to the drainage gap, and the other end is connected to the mud pool 11. The drainage pipe 23 is also connected to a water pump 231, which provides power to transport the mud in the mud pool 11 through the drainage pipe 23 into the drainage gap. The axis of the drainage pipe 23 is parallel to the horizontal direction, and the projection of the axis of the drainage pipe 23 in the axial direction of the pile hole 1 is a tangent to the outer wall of the inner tube 22. That is, when mud enters the drainage gap, it rotates within the drainage gap under the guidance of the outer wall of the inner tube 22 and the inner wall of the outer tube 21. A plurality of drainage holes 221 are provided on the inner tube 22 near the bottom of the pile hole 1 . The plurality of drainage holes 221 are arranged in a circular array with the axis of the foundation pit casing 2 as the center. The mud in the drainage gap eventually enters the pile hole 1 through the drainage holes 221 .

[0036] like Figure 2 、 3As shown in Figure 4, the drainage mechanism 3 includes a homogenizing component 4, which is used to improve the uniformity of the slurry distribution in the circumferential direction of the foundation pit casing 2 when it flows to the drainage hole 221. The homogenizing component 4 includes a flow balancing rotor 41, which is composed of a pressure control ring plate 412, a flow balancing ring plate 411 and a number of power sailboards 413. The flow balancing ring plate 411 is located in the drainage gap and is coaxially connected to the foundation pit casing 2. The shape of the pressure control ring plate 412 is the same as that of the flow balancing ring plate 411, and the two plate surfaces are parallel to each other; a number of power sailboards 413 are arranged in a circular array and fixedly connected to the upper plate surface of the flow balancing ring plate 411, the plate surface of the power sailboard 413 is perpendicular to the plate surface of the flow balancing ring plate 411, and the end of the power sailboard 413 away from the flow balancing ring plate 411 is fixedly connected to the lower plate surface of the pressure control ring plate 412. A number of slurry holes 415 are provided on the flow balancing ring plate 411. The slurry holes 415 are arranged in a ring array with the axis of the flow balancing ring plate 411 as the center, and the projection of the drainage pipe 23 in the horizontal direction is within the height range of the power sailboard 413. That is, the impact force generated when the mud fluid rushes into the drainage gap can act as a thrust on the power sailboard 413, driving the flow balancing rotor 411 to rotate in a certain direction. At the same time, the mud between the pressure control ring plate 412 and the flow balancing ring plate 411 can continue to flow downward through the slurry holes 415; and due to the existence of the equalizing pressure holes 414, when the injection power of the mud is continuously increased, the hydraulic pressure between the power sailboards 413 can be equalized, and the flow distribution along the circumference of the flow balancing rotor 41 is also more balanced when the mud penetrates downward.

[0037] like Figure 2 、 3 As shown in Figure 4, a plurality of speed regulating holes 416 are also provided on the flow balancing ring plate 411. The plurality of speed regulating holes 416 are also arranged in a ring array with the axis of the flow balancing ring plate 411 as the center to form a circle, and the circle formed by them is located at the outer edge of the circle formed by the slurry holes 415. The speed regulating holes 416 can also allow mud to cross the flow balancing ring plate 411. A speed regulating plate 42 is slidably connected to the lower plate surface of the flow balancing ring plate 411 and at the speed regulating holes 416. The sliding direction is the radial direction of the flow balancing ring plate 411 and the plate surface of the speed regulating plate 42 is in contact with the plate surface of the flow balancing ring plate 411. The homogenizing assembly 4 also includes a control member for controlling the movement of the speed regulating plate 42. In this embodiment, the control member is a centrifugal spring 43. The expansion and contraction direction of the centrifugal spring 43 is also the radial direction of the flow balancing ring plate 411. One end of the centrifugal spring 43 is fixedly connected to the flow balancing ring plate 411, and the other end is fixedly connected to the speed regulating plate 42. In the natural state, the speed regulating plate 42 blocks the speed regulating hole 416. When the mud flow rate needs to be increased, the power of the water pump 231 is increased, the fluid pressure is increased, and the speed of the equalizing rotor 41 is increased. Under the action of centrifugal force, the speed regulating plate 42 tends to move away from the inner tube 22, the centrifugal spring 43 is compressed, and the speed regulating hole 416 is opened. The higher the speed, the greater the degree of opening of the speed regulating hole 416, and the higher the rate at which the mud passes through the equalizing ring plate 411.

[0038] like Figure 1 、 4 As shown in Figure 5, the drainage mechanism 3 also includes a drainage plate 31, which is hinged to the side of the inner tube 22 facing the slurry extraction drill rod 12, and its hinge axis is located below the drainage hole 221; in this embodiment, the number of drainage holes 221 and the number of drainage plates 31 are both eight and the two correspond one to one. A torsion spring (not shown in the figure) is installed on the hinge shaft between the guide plate 31 and the inner tube 22. The torsion spring applies a torsional force to the guide plate 31 to flip it upward. In a natural state, the guide plate 31 remains in contact with the inner wall of the inner tube 22 and closes the drainage hole 221. When mud is ejected from the drainage hole 221, the mud impacts the guide plate 31, causing it to flip downward. When each guide plate 31 is flipped to the side and abuts against each other, all the guide plates 31 are assembled into an annular plate, which further guides the mud ejected from the drainage hole 221, allowing the mud to rush toward the slurry extraction pipe more smoothly, thereby reducing the probability of the mud contacting the inner wall of the pile hole 1 here. In order to reduce the situation where mud passes through the gap between adjacent guide plates 31, a receiving groove 311 is opened on the side edge of each guide plate 31, and a seam membrane 32 is fixedly connected between each two adjacent guide plates 31. The seam membrane 32 is an elastic geomembrane, and its two ends are respectively fixedly connected to the bottom of the receiving groove 311. During the flipping process of the guide plate 31, the adjacent guide plates 31 are always connected and the gap is closed through the seam membrane 32, which can also improve the synchronization of each guide plate 31 during operation.

[0039] The implementation principle of the reverse circulation construction device for bored piles of bridges in the embodiment of the present application is as follows:

[0040] After the water pump 231 is started, the mud in the mud pool 11 is pumped into the foundation pit casing 2. Under the action of the flow equalizing component, the mud is evenly distributed along the circumference of the foundation pit casing 2 and sprayed to the grouting drill rod 12. Under the adsorption effect of the liquid, the mud flows downward along the grouting drill rod 12. During the entire process, there is almost no high-speed downstream liquid in contact with the inner wall of the pile hole 1, and the risk of collapse of the soil structure on the inner wall of the pile hole 1 is reduced.

[0041] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A reverse circulation construction device for bored piles of bridges, comprising a foundation pit casing (2), wherein the foundation pit casing (2) is coaxially embedded in the opening of a pile hole (1), a grouting drill rod (12) is coaxially penetrated in the pile hole (1), and a slurry pool (11) is opened on the ground next to the pile hole (1), characterized in that: A drainage pipe (23) is fixedly connected to the foundation pit casing (2), one end of the drainage pipe (23) is in communication with the mud pool (11), and the other end is in communication with the inner cavity of the foundation pit casing (2) and the pile hole (1). A drainage mechanism (3) is provided on the foundation pit casing (2), and the drainage mechanism (3) is used to allow mud to flow from the foundation pit casing (2) to the slurry extraction drill rod (12). A water pump (231) is provided on the drainage pipe (23); The foundation pit casing (2) comprises an outer cylinder (21) and an inner cylinder (22) which are coaxially fixedly connected to each other, a drainage gap is formed between the outer cylinder (21) and the inner cylinder (22), a plurality of drainage holes (221) are provided on the inner cylinder (22), and the plurality of drainage holes (221) are arranged in a circular array with the axis of the foundation pit casing (2) as the center, and the drainage mechanism (3) comprises a drainage plate (31), the drainage plate (31) is located on the side of the inner cylinder (22) facing the grouting drill rod (12), and the drainage plate (31) is located below the drainage hole (221); The axis of the drainage pipe (23) is parallel to the horizontal direction, and the projection of the axis of the drainage pipe (23) in the axial direction of the pile hole (1) is a tangent to the outer wall of the inner tube (22). The drainage mechanism (3) also includes a homogenizing component (4), and the homogenizing component (4) is used to improve the uniformity of the distribution of mud in the circumferential direction of the foundation pit casing (2) when the mud flows to the drainage hole (221); The slurry assembly (4) includes a flow-equalizing rotor (41), the flow-equalizing rotor (41) is coaxially connected to the foundation pit casing (2), the flow-equalizing rotor (41) includes a flow-equalizing ring plate (411) and a plurality of power sailboards (413), the flow-equalizing ring plate (411) is located in the drainage gap and is coaxial with the foundation pit casing (2), the plurality of power sailboards (413) are arranged in a ring array and fixedly connected to the flow-equalizing ring plate (411), the projection of the drainage pipe (23) in the horizontal direction is located within the height range of the power sailboard (413), and the flow-equalizing ring plate (411) is provided with a plurality of slurry holes (415) that pass through the thickness of the flow-equalizing ring plate; The surface of the power sailboard (413) is perpendicular to the surface of the flow-equalizing ring plate (411); each power sailboard (413) is fixedly connected to the same pressure-controlling ring plate (412) on one side away from the flow-equalizing ring plate (411); the shape of the pressure-controlling ring plate (412) is consistent with that of the flow-equalizing ring plate (411); and each power sailboard (413) is provided with a pressure-equalizing hole (414).

2. A bridge bored pile reverse circulation construction device according to claim 1, characterized in that: The guide plate (31) is hinged to the inner cylinder (22), and the hinge axis of the two is located below the guide hole (221). A torsion spring is provided on the hinge axis of the guide plate (31) and the inner cylinder (22), and the torsion spring applies a torsional force to flip the guide plate (31) upward.

3. A bridge bored pile reverse circulation construction device according to claim 2, characterized in that: A joint membrane (32) is fixedly connected between adjacent drainage plates (31), wherein the joint membrane (32) is an elastic geomembrane, and a receiving groove (311) for the joint membrane (32) is provided on the side edge of the drainage plate (31).

4. A bridge bored pile reverse circulation construction device according to claim 1, characterized in that: The flow-equalizing ring plate (411) is provided with a speed regulating hole (416), and a speed regulating plate (42) is movably connected to the flow-equalizing ring plate (411) at the speed regulating hole (416). The plate surface of the speed regulating plate (42) is in contact with the plate surface of the flow-equalizing ring plate (411), and the speed regulating plate (42) is movable to control the closing or opening of the speed regulating hole (416). The homogenizing assembly (4) further includes a control component for controlling the movement of the speed regulating plate (42).

5. A bridge bored pile reverse circulation construction device according to claim 4, characterized in that: The speed regulating plate (42) is slidably connected to the flow averaging ring plate (411), and the sliding direction is the radial direction of the flow averaging ring plate (411). The control component is a centrifugal spring (43), and the expansion and contraction direction of the centrifugal spring (43) is the radial direction of the flow averaging ring plate (411). One end of the centrifugal spring (43) is fixedly connected to the flow averaging ring plate (411), and the other end is fixedly connected to the speed regulating plate (42).

Images