A grouting device for locking the water stop of a steel pipe pile cofferdam

Abstract

The present application relates to a kind of for locking steel pipe pile cofferdam water stop pressure grouting device, including a support frame, pressure grouting pipe, annular air bag and inflation pipe;The support frame includes upper support plate and lower support plate, there is a certain interval between upper support plate and lower support plate and welding connecting rod, multiple buckles are arranged in equidistance rotation on the edge of upper support plate, and the lower end of buckle is located below upper support plate and is inclined to the outside of upper support plate upwards;Pressure grouting pipe vertically penetrates upper support plate and lower support plate;Annular air bag is located between the upper support plate and lower support plate of support frame, annular air bag can extrude the lower end of buckle to rotate to the outside of upper support plate in inflation state, and its annular outside surface protrudes to the outside of upper support plate and lower support plate;Inflation pipe penetrates upper support plate and inflates and deflates air bag.The present application can be combined with rock by the way of high-pressure grouting to press cement slurry from inside steel pipe pile to outside steel pipe pile, so that steel pipe pile is closely combined with rock, and the water stop effect of steel pipe pile cofferdam is improved.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology and relates to a construction method for locking steel pipe pile cofferdams, specifically a grouting device for water-stopping locking steel pipe pile cofferdams. Background Technology

[0002] Cofferdams are commonly used as temporary water-retaining structures in the construction of bridge foundations in underwater areas. Common types of cofferdams include island cofferdams, sheet pile cofferdams, steel pipe pile cofferdams, and single- or double-walled steel cofferdams. Among them, steel pipe pile cofferdams have advantages such as low cost, convenient construction, and recyclability, and are suitable for deep-water construction. Therefore, steel pipe pile cofferdams are often used in deep-water foundation construction. However, steel pipe pile cofferdams are difficult to control for leakage. Therefore, improving the water-stopping effect of steel pipe pile cofferdams is the key to ensuring the smooth progress of construction.

[0003] like Figure 1 , Figure 2 , Figure 3 As shown, the steel pipe pile cofferdam is a closed-loop structure composed of multiple steel pipe piles 13. The lower ends of the steel pipe piles 13 are driven to a certain depth into the rock stratum 16 below the riverbed overburden layer 15. Each steel pipe pile has locking buckles 14 on both sides, and adjacent steel pipe piles are connected by locking buckles. The steel pipe piles are usually driven using a vibratory pile hammer. The vibration impact of the lower end of the steel pipe pile on the rock stratum breaks the rock and causes the steel pipe pile to sink, resulting in a certain gap between the steel pipe pile and the rock stratum. If water from outside the cofferdam seeps into the gap between the steel pipe pile and the rock stratum, it will further enter the cofferdam from the bottom of the steel pipe pile. In addition, since the locking buckles 14 are rigid structures, if the interlocking locking buckles are not sealed tightly, water from outside the cofferdam will also enter the cofferdam through the gaps in the locking buckles. Therefore, the main leakage points of the steel pipe pile cofferdam are the bottom of the steel pipe piles and the locking buckles.

[0004] For leaks in the locking mechanism, filling the locking mechanism with grease, cotton wool, or wooden wedges can achieve a good water-stopping effect. For leaks at the bottom of the steel pipe pile, the usual method is to inject cement grout into the steel pipe pile to seal the bottom. However, due to the low grouting pressure, the cement grout inside the steel pipe pile does not easily diffuse to the outside to seal the gap between the outer wall of the steel pipe pile and the rock stratum. Moreover, even if a small amount of cement grout overflows between the steel pipe pile and the rock stratum, the small gap between the steel pipe pile and the rock stratum makes it impossible to form a seal between the steel pipe pile and the rock stratum. The steel pipe piles are not effectively consolidated, so they are prone to swaying under the impact of water flow. This causes the bottom concrete to fail to bond firmly with the rock stratum, allowing water outside the cofferdam to seep into the bottom of the steel pipe piles through the gaps between them and the rock stratum. As a result, the water-stopping effect is not ideal, especially when the riverbed cover is a pebble layer. Due to the high permeability of the pebble layer, a large amount of water will enter the gaps between the outer wall of the steel pipe piles and the rock stratum and enter the cofferdam through the bottom of the steel pipe piles, seriously affecting the construction safety inside the cofferdam. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a grouting device for locking steel pipe pile cofferdams to improve the water-stopping effect of steel pipe pile cofferdams and ensure the safety of steel pipe pile cofferdam construction.

[0006] The technical solution of the present invention is as follows:

[0007] A grouting device for water-stopping a cofferdam made of locking steel pipe piles, characterized in that it includes a support frame, a grouting pipe, an annular airbag, and an inflation pipe;

[0008] The support frame includes an upper support plate and a lower support plate arranged in parallel. The upper and lower support plates are circular plates of equal size. There is a certain distance between the upper and lower support plates and multiple connecting rods are welded on them. The upper support plate has at least three slots equidistantly opened around its edge. An ear plate is welded to both sides of each slot on the top surface of the upper support plate. A buckle is provided in each slot. The upper end of the buckle is rotatably connected to the two ear plates by a pin. The lower end of the buckle extends below the upper support plate and tilts outward from the upper support plate.

[0009] The grouting pipe passes through the upper and lower support plates in a direction perpendicular to the upper and lower support plates of the support frame, and the grouting pipe is welded to the upper and lower support plates.

[0010] The annular airbag is located between the upper and lower support plates of the support frame. The axis of the annular airbag coincides with the axis of the upper and lower support plates. An inflation port is provided on the inner side of the annular airbag. When the annular airbag is not inflated, its top surface is a certain distance away from the bottom surface of the upper support plate and the lower end of the buckle. When the annular airbag is inflated, its top and bottom surfaces press against the upper and lower support plates respectively and squeeze the lower end of the buckle to rotate outward from the upper support plate. Its annular outward side protrudes outward from the upper and lower support plates.

[0011] The inflation tube passes through the upper support plate, and the lower end of the inflation tube is fixedly connected to the inflation port on the inner side of the annular airbag.

[0012] This invention can form a sealed space inside the steel pipe pile. Cement grout can be injected from inside the steel pipe pile into the outside of the steel pipe pile through high-pressure grouting, filling the gap between the steel pipe pile and the rock strata and making the steel pipe pile and the rock strata tightly bonded. This allows the steel pipe pile to resist the impact of water flow and remain stable, and can prevent water from outside the cofferdam from entering the cofferdam from the bottom of the steel pipe pile, thus achieving a good water-stopping effect. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the plan structure of a steel pipe pile cofferdam;

[0014] Figure 2 This is a schematic diagram of the steel pipe pile interlocking connection structure of a steel pipe pile cofferdam;

[0015] Figure 3This is a schematic diagram of the elevation structure of a steel pipe pile cofferdam;

[0016] Figure 4 This is a schematic diagram of the elevation structure of the annular airbag during the inflatation of the present invention;

[0017] Figure 5 This is a schematic diagram of the elevation structure of the present invention during the inflation of the annular airbag.

[0018] Figure 6 This is a schematic diagram of the planar structure of the present invention;

[0019] Figure 7 This is a schematic diagram of the planar structure of the upper support plate;

[0020] Figure 8 This is a schematic diagram of the planar structure of the annular airbag;

[0021] Figure 9 This is a schematic diagram of the steel pipe pile structure of the steel pipe pile cofferdam when grouting is performed using the present invention;

[0022] Figure 10 This is a schematic diagram of the structural state of forming a steel pipe pile hole by vibrating a large-diameter steel casing;

[0023] Figure 11 This is a schematic diagram showing the state of the steel casing after it has been pulled out.

[0024] Figure 12 This is a schematic diagram showing the state of a steel pipe pile inserted into a pile hole and a grouting device installed inside the steel pipe pile.

[0025] Figure 13 This is a schematic diagram showing the state of the grouting device during grouting construction inside the steel pipe pile. Detailed Implementation

[0026] like Figures 4 to 8 As shown, the present invention includes a support frame, a grouting pipe 1, an annular airbag 2, and an inflation pipe 3;

[0027] The support frame includes an upper support plate 4 and a lower support plate 5 arranged in parallel. The upper support plate and the lower support plate are circular plates of equal size. There is a certain distance between the upper support plate 4 and the lower support plate 5 and multiple connecting rods 6 are welded thereon. At least three slots 41 are equidistantly opened around the edge of the upper support plate 4. An ear plate 7 is welded to both sides of each slot 41 on the top surface of the upper support plate. A buckle 8 is provided in each slot 41. The upper end of the buckle 8 is rotatably connected to the two ear plates 7 through a pin 9. The lower end of the buckle 8 extends below the upper support plate and is inclined outward from the upper support plate 4.

[0028] The grouting pipe 1 passes through the upper support plate 4 and the lower support plate 5 in a direction perpendicular to the upper support plate 4 and the lower support plate 5 of the support frame, and the grouting pipe 1 is welded to the upper support plate 4 and the lower support plate 5.

[0029] like Figure 8 As shown, the structure of the annular airbag 2 is similar to that of a rubber tire; as Figure 4 , Figure 5 As shown, the annular airbag 2 is located between the upper support plate 4 and the lower support plate 5 of the support frame. The axis of the annular airbag coincides with the axis of the upper and lower support plates, and an inflation port is provided on the inner side of the annular airbag; Figure 4 As shown, when the annular airbag 2 is not inflated, there is a certain distance between its top surface and the bottom surface of the upper support plate and the lower end of the buckle; as Figure 5 As shown, when the annular airbag 2 is inflated, its top and bottom surfaces press against the upper and lower support plates respectively and squeeze the lower end of the buckle 8 to rotate outward from the upper support plate, and its annular side protrudes outward from the upper and lower support plates.

[0030] The inflation tube 3 passes through the upper support plate 4, and the lower end of the inflation tube 3 is fixedly connected to the inflation port on the inner side of the annular airbag 2.

[0031] In a specific implementation of the present invention, in order to ensure that the buckle can rotate smoothly outward when squeezed by the airbag, the buckle 8 can be set as S-shaped, with its upper end bent inward to the upper support plate and rotatably connected to the two ear plates through a pin, and its lower end bent outward to the upper support plate.

[0032] Furthermore, a spring 10 can be connected between the lower end of the buckle 8 and the bottom surface of the upper support plate 4. The spring is arranged along the radial direction of the upper support plate. The spring 10 is a tension spring. One end of the spring is welded to the lower end of the buckle, and the other end is welded to the bottom surface of the upper support plate. In its natural state, the lower end of the buckle 8 is located within the edge range of the upper support plate 4. In the stretched state, the lower end of the buckle rotates to the outside of the upper support plate and protrudes a certain length beyond the edge range of the upper support plate.

[0033] In a specific implementation of the present invention, in order to ensure that the stress is uniform throughout the steel pipe pile during grouting, the grouting pipe 1 can pass through the center of the upper support plate 4 and the lower support plate 5, and the lower end of the grouting pipe can extend to a certain length below the lower support plate.

[0034] The invention is used as follows:

[0035] like Figure 9 As shown, a ring-shaped limiting plate 11 is welded circumferentially near the lower end of each steel pipe pile 13 in the steel pipe pile cofferdam. The distance between the limiting plate and the bottom of the steel pipe pile is generally no more than the designed driving depth of the steel pipe pile in the riverbed rock strata. The inner diameter of the ring-shaped limiting plate should be greater than the diameter of the upper and lower support plates of the grouting device. Multiple grout outlet holes 12 are opened on the wall of the steel pipe pile 13 below the limiting plate. The distance between each grout outlet hole and the ring-shaped limiting plate should be greater than the spacing between the upper and lower support plates of the grouting device.

[0036] like Figure 10 , Figure 11 As shown, before each steel pipe pile 13 of the cofferdam is driven, a steel casing 17 is first driven at the designed driving position of each steel pipe pile. The diameter of the steel casing is larger than the diameter of the steel pipe pile. The steel casing 17 is driven into the rock stratum 16 below the riverbed cover layer 15 to the designed driving depth of the steel pipe pile, forming a large-diameter pile hole. Clay 18 is backfilled into the steel casing 17, and the clay backfilling is not lower than the height of the riverbed cover layer. Then the steel casing is pulled out, and the clay 18 remains in the pile hole.

[0037] like Figure 12 As shown, a steel pipe pile 13 is inserted into the pile hole formed by the steel casing, and the axis of the steel pipe pile is aligned with the center of the pile hole as much as possible; the clay inside the steel pipe pile 13 is removed, and at this time the outer wall of the steel pipe pile 13 and the rock layer 16 are completely filled with clay 18; a grouting device is placed inside the steel pipe pile. When the grouting device is placed, the air bag 2 is not inflated. The support frame of the grouting device is placed below the annular limiting plate 11, and the upper ends of the grouting pipe 1 and the air inflator 3 are located outside the upper end of the hole of the steel pipe pile.

[0038] like Figure 13 As shown, the airbag 2 is inflated through the inflation pipe 3. During the inflation process, the airbag 2 compresses the lower end of the buckle 8 and rotates outward until the lower end of the buckle 8 approaches or presses against the inner wall of the steel pipe pile 13. After the airbag is fully inflated, the airbag 2 is tightly pressed against the inner wall of the steel pipe pile 13, forming a sealed space between the airbag 2, the lower support plate 5, and the lower end of the steel pipe pile 13. Then, cement grout is injected into the lower end of the steel pipe pile through the grouting pipe 1. During the injection process, the high-pressure cement grout 19 pushes the support frame upward. When the buckle 8 contacts the bottom surface of the annular limiting plate 11, the annular limiting plate 11 will prevent the support frame from continuing to move upward. As the pressure of the cement grout inside the steel pipe pile increases, the cement grout 19 will overflow from the grout outlet on the steel pipe pile under high pressure, squeezing the clay 18 between the steel pipe pile 13 and the rock layer 16. The clay 18 gradually moves upward after being squeezed, while the high-pressure cement grout 19 gradually fills the space between the steel pipe pile and the rock layer until the cement grout completely replaces the clay between the steel pipe pile and the rock layer, at which point grouting stops. After the cement grout 19 solidifies, it can firmly bond the steel pipe pile to the rock layer, enabling the steel pipe pile to resist the impact of water flow and remain stable. At the same time, the cement grout can completely seal the gap between the steel pipe pile and the rock layer, preventing external water from entering the space between the steel pipe pile and the rock layer.

[0039] After grouting of a steel pipe pile is completed, the airbag is deflated and retracted. Under the action of the tension spring, the lower end of the buckle 8 rotates towards the inner side of the upward support plate, and the grouting device returns to its original state. Figure 12 The state shown indicates that the grouting device can be easily removed from the steel pipe pile.

[0040] Each steel pipe pile of the steel pipe pile cofferdam is installed in accordance with the above method. After the cofferdam is formed, it can effectively prevent water from outside the cofferdam from entering the cofferdam through the gaps between the steel pipe piles, thereby ensuring the safety of construction inside the cofferdam.

Claims

1. A grouting device for sealing water in a cofferdam made of interlocking steel pipe piles, characterized in that: It includes a support frame, a grouting pipe, an annular airbag, and an inflation pipe; The support frame includes an upper support plate and a lower support plate arranged in parallel. The upper and lower support plates are circular plates of equal size. There is a certain distance between the upper and lower support plates and multiple connecting rods are welded on them. The upper support plate has at least three slots equidistantly opened around its edge. An ear plate is welded to both sides of each slot on the top surface of the upper support plate. A buckle is provided in each slot. The upper end of the buckle is rotatably connected to the two ear plates by a pin. The lower end of the buckle extends below the upper support plate and tilts outward from the upper support plate. The grouting pipe passes through the upper and lower support plates in a direction perpendicular to the upper and lower support plates of the support frame, and the grouting pipe is welded to the upper and lower support plates. The annular airbag is located between the upper and lower support plates of the support frame. The axis of the annular airbag coincides with the axis of the upper and lower support plates. An inflation port is provided on the inner side of the annular airbag. When the annular airbag is not inflated, its top surface is a certain distance away from the bottom surface of the upper support plate and the lower end of the buckle. When the annular airbag is inflated, its top and bottom surfaces press against the upper and lower support plates respectively and squeeze the lower end of the buckle to rotate outward from the upper support plate. Its annular outward side protrudes outward from the upper and lower support plates. The inflation tube passes through the upper support plate, and the lower end of the inflation tube is fixedly connected to the inflation port inside the annular airbag. A ring-shaped limiting plate is welded circumferentially inside each steel pipe pile of the steel pipe pile near the lower end of the steel pipe pile. The inner diameter of the ring-shaped limiting plate is larger than the diameter of the upper and lower support plates of the grouting device. The support frame of the grouting device is lowered below the ring-shaped limiting plate.

2. The grouting device for water-stopping cofferdams using interlocking steel pipe piles according to claim 1, characterized in that: The buckle is S-shaped, with its upper end bent inwards towards the upper support plate and rotatably connected to the two ear plates via a pin, and its lower end bent outwards towards the upper support plate.

3. The grouting device for water-stopping cofferdams using interlocking steel pipe piles according to claim 2, characterized in that: A spring is connected between the lower end of the buckle and the bottom surface of the upper support plate. The spring is arranged along the radial direction of the upper support plate. One end of the spring is welded to the lower end of the buckle, and the other end is welded to the bottom surface of the upper support plate. In its natural state, the lower end of the buckle is located within the edge range of the upper support plate. In the stretched state, the lower end of the buckle rotates to the outside of the upper support plate and protrudes a certain length beyond the edge range of the upper support plate.

4. The grouting device for water-stopping cofferdams using interlocking steel pipe piles according to claim 1, characterized in that: The grouting pipe passes through the center of the upper and lower support plates.

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