A drag-reducing expanding anti-seismic sleeve for precast piles and a construction method thereof

Abstract

The application discloses a drag-reducing and diameter-enlarging anti-seismic sleeve for precast piles and a construction method, which comprises a drag-reducing and diameter-enlarging anti-seismic sleeve, diameter-enlarging rubber and a blade foot; the diameter-enlarging rubber is symmetrically arranged outside the drag-reducing and diameter-enlarging anti-seismic sleeve; the blade foot with a bottom annular cavity and a drag-reducing channel is installed at the bottom of the drag-reducing and diameter-enlarging anti-seismic sleeve; a first annular channel with a cement mortar pouring opening and an exhaust opening is arranged in the top of the sleeve; a plurality of first vertical channels with cement mortar channels are connected; the cement mortar channel outlet is connected to the diameter-enlarging rubber; a second annular channel with a drainage opening is arranged outside the drag-reducing and diameter-enlarging anti-seismic sleeve and is connected to a plurality of drainage channels in the sleeve wall; a plurality of third vertical channels are arranged in the sleeve wall of the drag-reducing and diameter-enlarging anti-seismic sleeve; a drag-reducing interface is arranged at the top; and the bottom is connected to the blade foot. The application not only effectively improves the sinking efficiency, but also can enlarge the diameter of the pile body after the sinking of the precast pile is completed, thereby improving the engineering anti-seismic level of the precast pile.

Description

Technical Field

[0001] This invention relates to the field of engineering foundation technology, and in particular to a drag-reducing and diameter-expanding seismic sleeve for precast piles and its construction method. Background Technology

[0002] Pile foundations not only ensure the smooth progress of engineering construction, but are also the key to the safe operation and maintenance of buildings or structures on them.

[0003] Precast piles, as a common type of pile foundation, are widely used in slope engineering, foundation pit engineering, and various earthquake-resistant engineering projects. Precast piles are driven using static or vibratory methods with a pile driver. If encountering soil layers that are difficult to penetrate, the increased driving force or vibration load may cause the pile to break or even crumble, adversely affecting its bearing capacity. Furthermore, the earthquake resistance of precast piles is a significant concern in the industry. The conventional approach is to embed drainage elements in the precast piles for earthquake-resistant drainage to prevent soil liquefaction disasters caused by earthquakes. However, embedding drainage elements greatly increases the processing difficulty of precast piles, leading to longer production times and potentially affecting project progress to some extent.

[0004] Therefore, in order to solve the problem of excessive driving resistance of precast piles causing structural damage, and at the same time improve the bearing capacity and seismic performance of precast piles, there is an urgent need for a convenient, efficient and reliable auxiliary driving equipment suitable for the construction of precast piles. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a drag-reducing and diameter-expanding seismic-resistant sleeve for precast piles and a construction method thereof. The technical solution adopted by this invention to solve its technical problem is as follows:

[0006] A drag-reducing and diameter-expanding seismic sleeve for precast piles includes a drag-reducing and diameter-expanding seismic sleeve, an expanded diameter rubber, and a cutting edge;

[0007] The expanded diameter rubber is symmetrically arranged around the outside of the drag-reducing and shock-resistant sleeve, and the edge of each expanded diameter rubber is sealed and fixedly connected to the drag-reducing and shock-resistant sleeve.

[0008] The cutting edge is located at the bottom of the drag-reducing and diameter-expanding anti-vibration sleeve; the bottom of the cutting edge is provided with an annular cavity and a drag-reducing channel;

[0009] The top of the drag-reducing and diameter-expanding seismic sleeve is provided with a first annular channel; the top of the first annular channel is provided with a cement mortar pouring port and an exhaust port, and the bottom is connected to several circumferentially distributed first vertical channels in the sleeve wall; a cement mortar channel is provided on the lower outer wall of the first vertical channel; the outlet of the cement mortar channel is connected to the part where the diameter-expanding rubber wraps the sleeve.

[0010] The drag-reducing and diameter-expanding seismic sleeve has a second annular channel on its outer side. The top of the second annular channel has a drain outlet, and the inner side has a groove that connects to several circumferentially distributed drain channels inside the sleeve wall. The lower outer wall of the drain channel has a drain hole that connects to the outside of the sleeve wall.

[0011] The cylinder wall of the drag-reducing and diameter-expanding anti-seismic sleeve is also provided with several circumferentially distributed third vertical channels; the top of the third vertical channel is provided with a drag-reducing interface, and the bottom is connected to the annular cavity in the cutting foot through a connecting pipe.

[0012] Furthermore, the inner diameter of the drag-reducing and diameter-expanding seismic sleeve is consistent with the outer diameter of the precast pile; the precast pile is a solid pile or a hollow pipe pile.

[0013] Furthermore, the number of the first vertical channels is the same as the number of expansion rubbers; after the expansion rubber reaches its maximum expansion limit, the apex exceeds the outer diameter range of the cutting edge.

[0014] Furthermore, the maximum outer diameter of the cutting edge should be greater than the maximum outer diameter of the drag-reducing and diameter-expanding seismic sleeve to prevent damage to the expansion rubber outside the drag-reducing and diameter-expanding seismic sleeve during the driving of the precast pile.

[0015] In addition to the annular cavity, the hollow area inside the cutting edge can be filled with concrete to improve the self-weight, strength and stability of the cutting edge.

[0016] Furthermore, the drainage channel is equipped with a filter layer to ensure that soil particles cannot pass through.

[0017] According to a second aspect of the specification, a construction method for a drag-reducing and diameter-expanding seismic sleeve for precast piles is provided, the method comprising the following steps:

[0018] S1. Fix the drag-reducing sleeve to the precast pile; hoist the precast pile with the drag-reducing sleeve installed to the designated area for driving and installation;

[0019] S2. Based on the drag reduction design requirements during the precast pile driving process and the site hydrogeological conditions, determine the drag reduction materials and drag reduction methods; inject the drag reduction materials into the cutting edge through the drag reduction interface, the third vertical channel, the connecting pipe, the annular cavity, and the drag reduction channel to assist the precast pile driving process.

[0020] S3. Control the verticality and speed of precast pile driving;

[0021] S4. During the driving process of precast piles, the excess pore water generated around the pile and the excess water generated by the drag-reducing material are discharged through the drainage channel, the second vertical channel, and the second annular channel via the drainage outlet.

[0022] S5. After the precast pile has driven to the design elevation, open the cement mortar pouring port and the vent. Pour cement mortar into the expanded diameter rubber through the cement mortar pouring port, the first annular channel, the first vertical channel, and the cement mortar channel. After cement mortar overflows from the vent, close the vent. Continue to inject cement mortar under pressure through the cement mortar pouring port until the expanded diameter rubber is in close contact with the surrounding soil. Stop injecting cement mortar and close the cement mortar pouring port.

[0023] S6. Repeat the above steps until all precast piles are installed.

[0024] Furthermore, in S1, the precast pile is compacted at the cutting edge to prevent the two from separating during the sinking process;

[0025] Furthermore, in S2, when the groundwater level is high, high-pressure water or high-pressure gas is preferred as drag-reducing material, and drag is reduced by injecting high-pressure water or gas at the design pressure; when the groundwater level is low, thixotropic mud is preferred as drag-reducing material, and drag is reduced by injecting thixotropic mud at the design pressure.

[0026] Furthermore, in S3, the verticality and speed of the precast pile driving are controlled by adjusting the injection speed and pressure of the drag-reducing material.

[0027] Furthermore, after the precast piles are installed, ensure that the drainage channel, the second vertical channel, and the second annular channel are unobstructed and keep the drainage outlet open; in the event of an earthquake, connect the drainage outlet to a water pump to promptly discharge excess pore water in the soil caused by the earthquake and prevent soil liquefaction damage.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention develops a drag-reducing and diameter-expanding seismic sleeve for precast piles, preferably manufactured using 3D printing technology in a single piece for easy industrial production. It not only reduces drag during precast pile driving, effectively improving driving efficiency, but also allows for pile diameter expansion after driving, significantly increasing the side friction resistance of the precast pile and greatly enhancing its early bearing capacity compared to traditional precast piles, thus effectively improving the overall bearing capacity of the precast pile. Furthermore, it ensures the precast pile can resist the effects of earthquake liquefaction damage during long-term operation, improving the seismic resistance of the precast pile.

[0030] In this invention, the drag-reducing material is determined according to the drag-reducing design requirements and the hydrogeological conditions of the site. It is adapted to local conditions. When the groundwater level is high, high-pressure water or high-pressure gas is preferred as the drag-reducing material, and drag is reduced by injecting high-pressure water or gas at the design pressure. When the groundwater level is low, thixotropic mud is preferred as the drag-reducing material, and drag is reduced by injecting thixotropic mud at the design pressure, so as to ensure that the drag reduction and penetration of the precast pile is efficient, energy-saving and environmentally friendly.

[0031] In this invention, the bottom of the drag-reducing and diameter-expanding seismic sleeve is provided with a cutting edge, which can break the soil better and facilitate the driving of precast piles; furthermore, a drag-reducing channel is provided at the bottom of the cutting edge, and drag-reducing material is injected to more effectively improve the drag-reduction efficiency.

[0032] In this invention, the diameter-enlarging rubber can expand the diameter of the precast pile by injecting cement mortar after the precast pile has been driven through. Combined with the drainage channel, it can discharge the excess pore water pressure in the soil around the precast pile, ensure that the precast pile is in close contact with the surrounding soil, increase the side friction resistance of the precast pile body, effectively improve the bearing capacity of the precast pile, and save the amount of cement mortar used.

[0033] The drainage channel in this invention not only meets the drainage needs during the driving process of precast piles, timely discharges excess pore water in the soil around the precast piles, reduces the disturbance of the drag-reducing material to the soil around the pile, increases the connection between the precast pile and the surrounding soil, and improves the bearing capacity of the precast pile; at the same time, during the long-term operation phase, it ensures that the excess water pressure generated under seismic loads can be discharged in a timely manner, prevents liquefaction damage of the soil around the precast piles, and greatly improves the seismic resistance of the precast piles. Attached Figure Description

[0034] Figure 1 Cross-sectional view of the drag-reducing and diameter-expanding seismic sleeve;

[0035] Figure 2 This is a cross-sectional view of AA.

[0036] Figure 3 This is a cross-sectional view of BB.

[0037] Figure 4 This is a CC cross-sectional view.

[0038] In the figure, the components are: drag-reducing and diameter-expanding seismic sleeve 1, first vertical channel 2, first annular channel 2-1, cement mortar pouring port 2-1-1, vent 2-1-2, cement mortar channel 2-2, second vertical channel 3, second annular channel 3-1, drain port 3-1-1, drain channel 3-2, third vertical channel 4, drag-reducing interface 4-1, connecting pipe 4-2, diameter-expanding rubber 5, cutting edge 6, annular cavity 6-1, and drag-reducing channel 6-2. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0040] A drag-reducing and diameter-expanding seismic sleeve for precast piles includes a drag-reducing and diameter-expanding seismic sleeve 1, a first vertical channel 2, a second vertical channel 3, a third vertical channel 4, an expanded diameter rubber 5, and a cutting edge 6.

[0041] Several first vertical channels 2, second vertical channels 3, and third vertical channels 4 are circumferentially and symmetrically arranged inside the drag-reducing and diameter-expanding seismic sleeve 1; the diameter-expanding rubbers 5 are circumferentially and symmetrically arranged in the drag-reducing and diameter-expanding seismic sleeve 1, with each edge of the diameter-expanding rubber being sealed and fixedly connected to the outside of the drag-reducing and diameter-expanding seismic sleeve (the diameter-expanding rubbers and the drag-reducing and diameter-expanding seismic sleeve can be sealed and fixedly connected by welding); the cutting edge 6 is located at the bottom of the drag-reducing and diameter-expanding seismic sleeve 1;

[0042] The first vertical channel 2 has a first annular channel 2-1 at the top and a cement mortar channel 2-2 on the side wall; the first annular channel 2-1 has a cement mortar pouring port 2-1-1 and an exhaust port 2-1-2; the first vertical channel 2 is connected to the expansion rubber 5 through the cement mortar channel 2-2; the outlet of the cement mortar channel is connected to the part of the expansion rubber that wraps around the sleeve;

[0043] The second vertical channel 3 is connected to the second annular channel 3-1 at the top, and a drainage channel 3-2 is provided on its side wall; the second annular channel 3-1 is located on the outside of the drag-reducing and diameter-expanding anti-seismic sleeve 1, and a drainage outlet 3-1-1 is provided on it; the third vertical channel 4 is provided with a drag-reducing interface 4-1 at the top; the bottom of the cutting edge 6 is provided with an annular cavity 6-1 and a drag-reducing channel 6-2; the third vertical channel 4 is connected to the annular cavity 6-1 through a connecting pipe 4-2. The third vertical channel 4 is a pair of symmetrically arranged channels, directly connected to 4-1, used for drag-reducing material transport; the first annular channel 2-1 is cut off at the third vertical channel 4, and the first annular channel 2-1 is not connected to the third vertical channel.

[0044] The aforementioned drag-reducing and diameter-expanding seismic sleeve for precast piles is preferably manufactured using 3D printing technology in a single piece; the inner diameter of the drag-reducing and diameter-expanding seismic sleeve 1 is consistent with the outer diameter of the precast pile; the precast pile can be a solid pile or a hollow pipe pile.

[0045] The quantity and size of the first vertical channel 2, the second vertical channel 3, the third vertical channel 4, and the expansion rubber 5 are determined by the diameter of the engineering foundation and the site's engineering geological conditions; the number of the first vertical channel 2 and the expansion rubber 5 are the same.

[0046] The arrangement of the first vertical channel 2, the first annular channel 2-1, the cement mortar pouring port 2-1-1, and the cement mortar channel 2-2 can meet the needs of cement mortar pouring inside the expanded diameter rubber 5.

[0047] The second vertical channel 3, the second annular channel 3-1, the drainage outlet 3-1-1 and the drainage channel 3-2 can meet the drainage needs during the precast pile driving process and the seismic drainage needs during the long-term operation phase.

[0048] The third vertical channel 4, the drag reduction interface 4-1, the connecting pipe 4-2, the annular cavity 6-1, and the drag reduction channel 6-2 are provided to meet the drag reduction requirements during the driving process of precast piles.

[0049] The drainage channel 3-2 is equipped with a filter layer to ensure that only water can pass through and soil particles cannot pass through.

[0050] According to engineering requirements, except for the annular cavity 6-1, the hollow area inside the cutting edge 6 can be filled with concrete to improve the self-weight, strength and stability of the cutting edge 6.

[0051] The maximum outer diameter of the cutting edge 6 should be greater than the maximum outer diameter of the drag-reducing and diameter-expanding seismic sleeve 1 and the diameter-expanding rubber 5 before the cement mortar is added, so as to prevent the diameter-expanding rubber 5 from being damaged or even destroyed during the driving of the precast pile.

[0052] Example 2

[0053] A construction method for a drag-reducing and diameter-expanding seismic sleeve for precast piles, the method comprising the following steps:

[0054] The drag-reducing sleeve is fixedly connected to the precast pile; the precast pile with the drag-reducing sleeve installed is hoisted to the designated area for driving and installation; the cutting edge 6 of the precast pile needs to be compacted to prevent the two from separating during the driving process;

[0055] Based on the drag reduction design requirements during the precast pile driving process and the site's hydrogeological conditions, the drag reduction materials and methods are determined. The drag reduction material is injected into the cutting edge 6 through the drag reduction interface 4-1, the third vertical channel 4, the connecting pipe 4-2, the annular cavity 6-1, and the drag reduction channel 6-2 to assist in the precast pile driving. When the groundwater level is high, high-pressure water or high-pressure gas is preferred as the drag reduction material, and drag is reduced by injecting high-pressure water or gas at the design pressure. When the groundwater level is low, thixotropic mud is preferred as the drag reduction material, and drag is reduced by injecting thixotropic mud at the design pressure. The design pressure of the drag reduction material should be greater than the shear strength of the soil at the driving depth.

[0056] Controlling the verticality and speed of precast pile driving; the verticality and speed of precast pile driving can be further controlled by adjusting the injection speed and pressure of drag-reducing material.

[0057] During the driving process of precast piles, excess pore water generated around the piles, as well as excess water generated by the drag-reducing material, are discharged through drainage channels 3-2, the second vertical channel 3, and the second annular channel 3-1 via drainage outlet 3-1-1. When the drag-reducing material is high-pressure water or thixotropic mud, the excess water generated by the drag-reducing material is excess water in the high-pressure water or thixotropic mud. The discharged water can be discharged into the drainage ditch via pipeline to prevent the discharged water from flowing directly into the ground surface around the precast piles.

[0058] After the precast piles have driven to the design elevation, open the cement mortar pouring port 2-1-1 and the vent 2-1-2; pour cement mortar into the expanded diameter rubber 5 through the cement mortar pouring port 2-1-1, the first annular channel 2-1, the first vertical channel 2, and the cement mortar channel 2-2; after cement mortar overflows from the vent 2-1-2, close the vent 2-1-2; continue to inject cement mortar under pressure through the cement mortar pouring port 2-1-1 until the expanded diameter rubber 5 is in close contact with the surrounding soil; stop injecting cement mortar and close the cement mortar pouring port 2-1-1; high-strength, fast-setting cement mortar is preferred; the maximum outer diameter of the drag-reducing, expanded diameter seismic sleeve 1 and the expanded diameter rubber 5 after the cement mortar has been poured should be greater than the maximum outer diameter of the cutting edge 6 to ensure that the expanded diameter rubber 5 is in close contact with the surrounding soil.

[0059] Repeat the above steps until all precast piles are installed.

[0060] Furthermore, after the precast piles are installed, ensure that the drainage channel 3-2, the second vertical channel 3, and the second annular channel 3-1 are unobstructed, and keep the drainage outlet 3-1-1 open; in the event of an earthquake, connect the drainage outlet 3-1-1 to a water pump to promptly discharge excess pore water in the soil caused by the earthquake and prevent soil liquefaction damage.

[0061] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A drag-reducing and diameter-expanding seismic-resistant sleeve for precast piles, characterized in that, This includes drag-reducing and diameter-expanding anti-seismic sleeves, diameter-expanding rubber, and cutting edges; The expanded diameter rubber is symmetrically arranged around the outside of the drag-reducing and shock-resistant sleeve, and the edge of each expanded diameter rubber is sealed and fixedly connected to the drag-reducing and shock-resistant sleeve. The cutting edge is located at the bottom of the drag-reducing and diameter-expanding anti-vibration sleeve; the bottom of the cutting edge is provided with an annular cavity and a drag-reducing channel; The top of the drag-reducing and diameter-expanding seismic sleeve is provided with a first annular channel; the top of the first annular channel is provided with a cement mortar pouring port and an exhaust port, and the bottom is connected to several circumferentially distributed first vertical channels in the sleeve wall; a cement mortar channel is provided on the lower outer wall of the first vertical channel; the outlet of the cement mortar channel is connected to the part where the diameter-expanding rubber wraps the sleeve. The drag-reducing and diameter-expanding seismic sleeve has a second annular channel on its outer side. The top of the second annular channel has a drainage outlet, and the inner side has a groove that connects to several circumferentially distributed drainage channels inside the sleeve wall. The lower outer wall of the drainage channel has a hole that connects to the outside of the sleeve wall. The cylinder wall of the drag-reducing and diameter-expanding anti-seismic sleeve is also provided with several circumferentially distributed third vertical channels; the top of the third vertical channel is provided with a drag-reducing interface, and the bottom is connected to the annular cavity in the cutting foot through a connecting pipe.

2. The drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 1, characterized in that, The inner diameter of the drag-reducing and diameter-expanding seismic sleeve is consistent with the outer diameter of the precast pile; the precast pile is a solid pile or a hollow pipe pile.

3. A drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 1, characterized in that, The number of the first vertical channels is the same as the number of expansion rubbers; after the expansion rubbers reach their maximum expansion limit, the apex exceeds the outer diameter range of the cutting edge.

4. A drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 1, characterized in that, The maximum outer diameter of the cutting edge should be greater than the maximum outer diameter of the drag-reducing and diameter-expanding seismic sleeve to prevent damage to the expansion rubber outside the drag-reducing and diameter-expanding seismic sleeve during the driving of the precast pile. In addition to the annular cavity, the hollow area inside the cutting edge can be filled with concrete to improve the self-weight, strength and stability of the cutting edge.

5. A drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 1, characterized in that, The drainage channel is equipped with a filter layer to prevent soil particles from passing through.

6. A construction method using the drag-reducing and diameter-expanding seismic sleeve for precast piles as described in any one of claims 1-5, characterized in that, The method includes the following steps: S1. Fix the drag-reducing sleeve to the precast pile; hoist the precast pile with the drag-reducing sleeve installed to the designated area for driving and installation; S2. Based on the drag reduction design requirements during the precast pile driving process and the site hydrogeological conditions, determine the drag reduction materials and drag reduction methods; inject the drag reduction materials into the cutting edge through the drag reduction interface, the third vertical channel, the connecting pipe, the annular cavity, and the drag reduction channel to assist the precast pile driving process. S3. Control the verticality and speed of precast pile driving; S4. During the driving process of precast piles, the excess pore water generated around the pile and the excess water generated by the drag-reducing material are discharged through the drainage channel, the second vertical channel, and the second annular channel via the drainage outlet. S5. After the precast piles have driven to the design elevation, open the cement mortar pouring port and the vent. Pour cement mortar into the expanded diameter rubber through the cement mortar pouring port, the first annular channel, the first vertical channel, and the cement mortar channel. After cement mortar overflows from the vent, close the vent. Continue to inject cement mortar under pressure through the cement mortar pouring port until the expanded diameter rubber is in close contact with the surrounding soil. Stop injecting cement mortar and close the cement mortar pouring port. S6. Repeat the above steps until all precast piles are installed.

7. A construction method for a drag-reducing and diameter-expanding seismic-resistant sleeve for precast piles according to claim 6, characterized in that, In S1, the precast pile is compacted at the cutting edge to prevent the two from separating during the sinking process.

8. A construction method for a drag-reducing and diameter-expanding seismic-resistant sleeve for precast piles according to claim 6, characterized in that, In S2, when the groundwater level is high, high-pressure water or high-pressure gas is selected as drag-reducing material, and drag is reduced by injecting high-pressure water or high-pressure gas at the design pressure; when the groundwater level is low, thixotropic mud is selected as drag-reducing material, and drag is reduced by injecting thixotropic mud at the design pressure.

9. A construction method for a drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 6, characterized in that, In S3, the verticality and speed of the precast pile driving are controlled by adjusting the injection speed and pressure of the drag-reducing material.

10. A construction method for a drag-reducing and diameter-expanding seismic sleeve for precast piles according to claim 6, characterized in that, After the precast piles are installed, ensure that the drainage channel, the second vertical channel, and the second ring channel are unobstructed and keep the drainage outlet open. In the event of an earthquake, connect the drainage outlet to a water pump to promptly drain excess pore water in the soil caused by the earthquake and prevent soil liquefaction damage.

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