Prefabricated pile and drainage well integrated device and construction method thereof

Abstract

The present invention discloses an integrated device of prefabricated piles and drainage wells and a construction method thereof, the device comprising: a prefabricated well structure, which is composed of a well pipe with a water-permeable side wall and a bottom connecting pipe with an impermeable side wall; a pile driver that is pulled out of the well hole after reaching a specified elevation, the prefabricated well structure can be detachably installed in the pile driver, and the prefabricated well structure is fixed in the well hole after the construction is completed; a pile top connector, the bottom connecting pipe is connected to the upper side of the pile top connector; a prefabricated pile, the prefabricated pile is connected to the lower side of the pile top connector. By combining the method of prefabricated piles and drainage wells to work in coordination, the drainage well adopts a prefabricated structure to avoid problems such as high energy consumption, long construction period, and uncontrollable quality of filter material backfilling during the well construction process, and at the same time avoids problems such as pile position deviation, inclined piles or floating due to untimely dissipation of excess pore water pressure during pile sinking.

Description

Technical Field

[0001] The invention relates to the technical field of construction engineering, in particular to a prefabricated pile and drainage well integrated device and a construction method thereof. Background Art

[0002] During the construction of underground projects, drainage wells can play a role in lowering the groundwater level. By pumping out groundwater, the soil in the construction area can be kept relatively dry, which is convenient for the construction process. This is crucial for projects such as foundation pit excavation, underground pipeline laying and underground structure construction. At present, conventional drainage wells use traditional high-energy consumption drilling construction technology and fill filter materials on site. Not only does it take a long time to complete the well, but the backfill quality of the filter material is difficult to guarantee, which affects the pumping efficiency of the drainage well. In addition, a large amount of waste mud is generated during the well completion process, which is not environmentally friendly.

[0003] Precast concrete piles have the advantages of low cost, fast construction speed, and reliable pile quality. They are suitable for soft soil, clay, silt, and fully weathered rock formations, and have been widely used in South China, Jiangsu, Zhejiang, and Shanghai. In recent years, large-tonnage static precast pipe pile construction technology has been developed across the country, and the maximum pile pressure of static pile drivers has reached 4000kN to 8000kN. Because it is a squeeze pile, the pile sinking process produces a squeeze effect, which generates very high pore water pressure. If it cannot be dissipated quickly, it will cause difficulties in pile sinking, causing vertical uplift and horizontal displacement of the soil, and affecting the deformation of surrounding buildings. In order to accelerate the dissipation of excess pore water pressure, conventional practices include pre-drilling drainage holes and setting up drainage sand wells, which not only require additional construction equipment, but also increase construction costs and extend construction periods. Summary of the invention

[0004] The purpose of the present invention is to provide an integrated device of prefabricated piles and drainage wells and a construction method thereof. By combining the prefabricated piles and drainage wells to work in coordination, the drainage well adopts a prefabricated structure to avoid problems such as high energy consumption, long construction period, and uncontrollable quality of filter material backfilling during the well construction process. At the same time, it avoids problems such as pile position deviation, inclined piles or floating caused by the untimely dissipation of excess pore water pressure during the pile sinking process.

[0005] The object of the present invention is achieved by: a prefabricated pile and drainage well integrated device, comprising:

[0006] A prefabricated well structure, which is composed of a well pipe and a bottom connecting pipe, wherein the bottom connecting pipe is fixedly connected to the bottom of the well pipe;

[0007] A pile driver is pulled out of the wellbore after reaching the designated elevation, wherein the prefabricated well structure is detachably installed in the pile driver, and the prefabricated well structure is fixed in the wellbore after the construction is completed;

[0008] A pile top connector, wherein the bottom connecting pipe is connected to the upper side of the pile top connector;

[0009] A precast pile connected to the underside of a pile top connector;

[0010] Before the pile driver is hoisted, a releasable temporary connection is formed between the bottom of the pile driver and the pile top connector; during the pile driving construction, the lower end of the pile driver is pressed downward to contact the pile top connector.

[0011] Furthermore, the well pipe includes a water-permeable pipe section and a water-impermeable pipe section, the water-permeable pipe section is water-permeable both inside and outside, and the water-impermeable pipe section is water-impermeable both inside and outside.

[0012] Furthermore, a sealing plate is packaged at the bottom of the bottom connecting pipe.

[0013] Furthermore, a groove is provided on the upper side of the pile top connector, and the prefabricated well structure and the pile driver are both plugged into the upper groove of the pile top connector.

[0014] Furthermore, a groove is provided on the lower side of the pile top connector, and the groove on the lower side of the pile top connector is fixedly sleeved on the upper end of the prefabricated pile.

[0015] Furthermore, the pile driver is connected with a plurality of releasable connecting steel cables, and the connecting steel cables are used to detachably and temporarily connect the pile driver and the pile top connector.

[0016] As another aspect of the present invention, a construction method is provided based on the above device, comprising the following steps:

[0017] S1, assembling the well pipe and the bottom connecting pipe, the assembled well structure is a prefabricated component, the well structure is installed in the pile driver, the bottom connecting pipe is connected to the pile top connector, and the bottom of the pile driver is temporarily connected to the pile top connector;

[0018] S2. According to the designed pile length, sink the precast piles in sections to the specified elevation;

[0019] S3, using a lifting device to move the pile driver equipped with the well structure to the pile position;

[0020] S4, aligning the pile top connector and the prefabricated pile, connecting the pile top connector and the prefabricated pile, and releasing the temporary connection between the bottom of the pile driver and the pile top connector;

[0021] S5. After the pile driver is pressed down to the specified elevation, the pile driver is pulled up to leave the pile top connector and the well structure in the soil;

[0022] S6. Construct nearby precast piles or pile wells and pump water from the pile wells according to demand.

[0023] When pumping water, place the water pump into the well pipe to perform the pumping operation.

[0024] The beneficial effects of the present invention are:

[0025] 1. Improve the quality of well completion. Use the method of casing pressure to avoid problems such as unqualified mud quality, hole collapse, shrinkage and bottom sediment in the conventional hole-forming process. Use prefabricated filter material (well pipe) to avoid on-site filling of filter material and other construction processes. The quality of the filter material can be controlled and inspected in advance, and the reliability is high;

[0026] 2. Reduce the well construction period. There is no need to drill holes or backfill filter materials during well construction, which simplifies the construction steps, reduces the amount of manual work on site, and saves well construction time;

[0027] 3. Accelerate the dissipation of excess pore water pressure, shorten the drainage path, reduce soil deformation, improve the protection effect of surrounding buildings, reduce pile position deviation, inclined piles, floating piles and other phenomena, and improve construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the integrated structure of prefabricated piles and drainage wells in the present invention.

[0029] Figure 2 It is a schematic diagram of prefabricated pile sinking in the present invention.

[0030] Figure 3 This is a schematic diagram of the construction of a dewatering well.

[0031] Figure 4 It is a construction diagram of the upper pull pile driver.

[0032] Figure 5 It is a schematic diagram of dewatering near precast piles or pile well construction.

[0033] Figure 6 It is a schematic diagram of the preferred pile-well connection cross section.

[0034] Figure 7 yes Figure 6 AA section view in.

[0035] Figure 8 It is a structural diagram of the well pipe.

[0036] Fig. 9 yes Figure 8 BB section view in.

[0037] Explanation of the reference numerals: 1. Well pipe; 2. Bottom connecting pipe; 3. Prefabricated pile; 4. Pile top connector; 5. Pile driver; 6. Inner pipe body; 7. Outer pipe body; 8. Closing plate; 9. Water pump; 10. Connecting steel cable. DETAILED DESCRIPTION

[0038] The following will be combined with the attached embodiment of the present invention Figure 1-9, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Combination Figure 1 , 5 As shown in , 6, a prefabricated pile and drainage well integrated device is provided, which includes:

[0040] The prefabricated well structure is composed of a well pipe 1 with a segmented side wall that is water-permeable and a bottom connecting pipe 2 with a side wall that is impermeable. The bottom connecting pipe 2 is fixedly connected to the bottom of the well pipe 1. The connection method includes but is not limited to bonding, clamping, tying or mechanical connection.

[0041] The pile driver 5 is pulled out of the wellbore after reaching the designated elevation. The prefabricated well structure is detachably installed in the pile driver 5. After the construction is completed, the prefabricated well structure is fixed in the wellbore. The outer wall of the well pipe 1 is fixedly fitted with the inner wall of the wellbore. The pile driver 5 is made of metal or concrete, and is hollow cylindrical or hollow rectangular. Its outer diameter is not larger than the inner diameter of the groove on the upper side of the pile top connector 4, and its inner diameter is not smaller than the outer diameter of the well pipe 1.

[0042] The pile top connector 4, the bottom connecting pipe 2 is connected to the upper side of the pile top connector 4;

[0043] The precast pile 3 is connected to the lower side of the pile top connector 4 .

[0044] Before the pile driver 5 is hoisted, a releasable temporary connection is formed between the bottom of the pile driver 5 and the pile top connector 4 to prevent the well pipe 1 and the bottom connecting pipe 2 from falling out of the pile driver 5 during the hoisting process; during the pile driving construction, the lower end of the pile driver 5 presses downward to contact the pile top connector 4, and the pile pressing force is transmitted to the top of the prefabricated pile 3 through the pile top connector 4.

[0045] like Figure 6-9 As shown, the well pipe 1 is composed of an inner pipe body 6 with a water-permeable segmented side wall and an outer pipe body 7, which can be a segmented combined structure. The inner pipe body 6 is fixedly connected to the outer pipe body 7, and the connection method includes but is not limited to bonding, binding or mechanical connection. The inner pipe body 6 is a metal or plastic pipe with segmented surface openings, and the outer pipe body 7 is a metal or porous thick-walled plastic pipe with water-permeable pores and a filter screen on the outside. The inner diameter of the outer pipe body 7 is not less than the outer diameter of the inner pipe body 6.

[0046] The bottom connecting pipe 2 is a metal or plastic pipe, which is watertight and adopts a segmented structure. Its top is connected to the bottom of the well pipe 1. The bottom connecting pipes of different sections, or the connection between the bottom connecting pipe 2 and the well pipe 1 can be glued, clamped, tied or mechanically connected. The bottom of the bottom connecting pipe 2 is encapsulated with a sealing plate 8. The sealing plate 8 is made of plastic or metal, and is glued, clamped, tied or mechanically connected to the bottom of the bottom connecting pipe 2; the bottom connecting pipe 2 is welded, glued, clamped or mechanically connected to the top of the pile top connector 4 below, but is not limited to the above connection methods.

[0047] The pile top connector 4 can be made of metal or concrete, and has a groove on its upper side. The prefabricated well structure and the pile driver 5 are both plugged into the upper groove of the pile top connector 4. The inner diameter of the upper groove of the pile top connector 4 is not less than the outer diameter of the pile driver 5, and the top of the pile top connector 4 is connected to the bottom of the bottom connecting pipe 2.

[0048] The pile top connector 4 is provided with a groove at the bottom, and the groove at the bottom of the pile top connector 4 is fixedly sleeved on the upper end of the precast pile 3. The inner diameter of the groove at the bottom of the pile top connector 4 is not less than the outer diameter of the precast pile 3, and can be nested in the top of the precast pile 3. The groove at the bottom of the pile top connector 4 and the top of the precast pile 3 are connected by welding, gluing, clamping or mechanical means, but are not limited to the above connection methods.

[0049] like Figure 6 As shown, the pile driver 5 is connected with a plurality of releasable connecting cables 10 , and the connecting cables 10 are used to detachably temporarily connect the pile driver 5 and the pile top connector 4 .

[0050] Based on the above device, a construction method is provided, and the specific steps are as follows:

[0051] S1, assembling the well pipe 1 and the bottom connecting pipe 2, the assembled well structure is a prefabricated component, such a well structure is installed in the pile driver 5, the bottom connecting pipe 2 is connected to the pile top connector 4, and the bottom of the pile driver 5 is temporarily connected to the pile top connector 4;

[0052] S2. According to the designed pile length, sink the precast pile 3 in sections to the specified elevation, such as Figure 2 As shown;

[0053] S3, using the lifting device to move the pile delivery device 5 equipped with the well structure to the pile position, such as Figure 3 As shown;

[0054] S4, aligning the pile top connector 4 and the prefabricated pile 3, connecting the pile top connector 4 and the prefabricated pile 3, and releasing the temporary connection between the bottom of the pile driver 5 and the pile top connector 4;

[0055] S5, after pressing the pile driver 5 down to the specified elevation, pull up the pile driver 5, and leave the pile top connector 4 and the well structure (well pipe 1 and bottom connecting pipe 2) in the soil. Figure 4 , 5 As shown;

[0056] S6. Construction of nearby prefabricated piles or pile wells, pumping of pile wells according to demand, such as Figure 5 As shown, a water pump 9 is placed in the well pipe 1 to perform a water pumping operation.

[0057] The following content provides a preferred application example, and you can choose other application examples according to project requirements.

[0058] The dewatering well structure includes a well pipe 1 and a bottom connecting pipe 2. Figure 8 As shown, the inner tube body 6 of the well pipe 1 is a PVC pipe of Φ200mm*4mm, with holes on the segmented surface, an opening rate of 20%, and a single section length of 3m. The thick-walled prefabricated filter material of the outer tube body 7 of the well pipe 1 is a plastic blind ditch pipe with an outer diameter of 300mm, an inner diameter of 200mm, and a single section length of 3m. The outer tube body 7 is wrapped with a layer of 100 mesh filter. The inner tube body 6 and the outer tube body 7 are connected by a rolled strip, and different sections of the well pipe 1 are connected by a DN300 PVC straight-through joint. The bottom connecting pipe 2 is a PVC pipe of Φ300mm*4mm, with a single section length of 0.5m, and a sealing plate 8 is provided below. The sealing plate 8 is a PVC pile cap with an outer diameter of Φ300mm, and is bonded to the bottom of the bottom connecting pipe 2 with PVC glue. The bottom connecting pipe 2 and the outer tube body 7 are connected by a Φ300mm clamp.

[0059] The pile top connector 4 is a steel ring with concave centers on both sides. The bottom is made of a steel ring of Φ516mm*8mm and a height of 300mm, and the top is made of a steel ring of Φ516mm*8mm and a height of 300mm. The top and bottom of the pile top connector 4 are welded through a middle steel plate of Φ516mm and a thickness of 12mm, and a steel ring is welded on the outside of the top of the pile top connector 4.

[0060] The prefabricated pile 3 (prestressed concrete pipe pile) adopts PHC500-A-125 pipe pile, the pile driver 5 adopts Φ480mm*10mm steel pipe, and two PVC8-10 steel ropes with a diameter of 8mm-10mm and a length of 80cm are arranged at the bottom of the pile driver 5. Both ends of the steel ropes are fixed to the steel rings welded on the outside of the pile driver 5.

[0061] The drainage well structure is assembled, and the well pipe 1 and the bottom connecting pipe 2 which have been spliced ​​are sent into a Φ480mm*10mm steel pipe pile driver 5, and the pile driver 5 is connected to the top of the pile top connector 4 with a connecting steel cable 10.

[0062] According to the design requirements, the total station GPS is used for positioning, and the PHC500-A-125 prestressed concrete pipe piles - precast piles are pressed to the specified depth in 3 sections using a pile driver. Figure 1 shown.

[0063] The pile driver 5 and the pile top connector 4 are hoisted to the position of the precast pile 3 , the pile top connector 4 is aligned with the precast pile 3 , and the pile top connector 4 is fixed to the top of the precast pile 3 by welding.

[0064] Release the PVC8-10 steel rope (connecting steel rope 10) connecting the pile driver 5 and the pile top connector 4, and use the pile driver 5 to press the well pipe 1, the bottom connecting pipe 2 and the prefabricated pile 3 to the specified design depth, such as Figure 3 shown.

[0065] Pull out the pile driver 5, leave the pile well structure in the soil, and complete the pile well construction. Figure 4 shown.

[0066] Construct adjacent pile wells or prefabricated pile foundations and use the pile wells for drainage as needed, such as Figure 5 shown.

[0067] The above application examples introduce an integrated structure and construction method of prefabricated piles and drainage wells, which can provide a simple, economical, effective and environmentally friendly method for future foundation pit drainage and similar drainage well construction.

[0068] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention; in the present invention, it should also be noted that the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through an intermediate connecting component, and the specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0069] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0070] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A prefabricated pile and drainage well integrated device, characterized in that: include: A prefabricated well structure, which is composed of a well pipe (1) and a bottom connecting pipe (2), wherein the bottom connecting pipe (2) is fixedly connected to the bottom of the well pipe (1); A pile driver (5) is pulled out of the wellbore after reaching the designated elevation, wherein the prefabricated well structure is detachably mounted in the pile driver (5), and the prefabricated well structure is fixed in the wellbore after the construction is completed; A pile top connector (4), wherein the bottom connecting pipe (2) is connected to the upper side of the pile top connector (4); A prefabricated pile (3), wherein the prefabricated pile (3) is connected to the lower side of the pile top connector (4); Before the pile driver (5) is hoisted, a releasable temporary connection is formed between the bottom of the pile driver (5) and the pile top connector (4); during pile driving construction, the lower end of the pile driver (5) contacts the pile top connector (4) with downward pressure.

2. The prefabricated pile and drainage well integrated device according to claim 1, characterized in that: The well pipe (1) comprises a water-permeable pipe section and a water-impermeable pipe section.

3. The prefabricated pile and drainage well integrated device according to claim 1, characterized in that: The bottom of the bottom connecting pipe (2) is sealed with a sealing plate (8).

4. The prefabricated pile and drainage well integrated device according to claim 1, characterized in that: The upper side of the pile top connector (4) is provided with a groove, and the prefabricated well structure and the pile driver (5) are both plugged into the upper side groove of the pile top connector (4).

5. The prefabricated pile and drainage well integrated device according to claim 1 or 4, characterized in that: A groove is provided on the lower side of the pile top connector (4), and the groove on the lower side of the pile top connector (4) is fixedly sleeved on the upper end of the prefabricated pile (3).

6. The prefabricated pile and drainage well integrated device according to claim 1, characterized in that: The pile driver (5) is connected to a plurality of releasable connecting steel cables (10), and the connecting steel cables (10) are used to detachably and temporarily connect the pile driver (5) and the pile top connector (4).

7. A construction method for implementing the prefabricated pile and drainage well integrated device according to claim 1, characterized in that: The steps include: S1, assembling a well pipe (1) and a bottom connecting pipe (2), wherein the assembled well structure is a prefabricated component, placing the well structure into a pile driver (5), connecting the bottom connecting pipe (2) to the pile top connector (4), and temporarily connecting the bottom of the pile driver (5) to the pile top connector (4); S2, sinking the precast piles (3) in sections to the specified elevation according to the designed pile length; S3, using a lifting device to move the pile driver (5) equipped with the well structure to the pile position; S4, aligning the pile top connector (4) and the prefabricated pile (3), connecting the pile top connector (4) and the prefabricated pile (3), and releasing the temporary connection between the bottom of the pile driver (5) and the pile top connector (4); S5, after the pile driver (5) is pressed down to a specified elevation, the pile driver (5) is pulled up to leave the pile top connector (4) and the well structure in the soil; S6. Construct nearby precast piles or pile wells and pump water from the pile wells according to demand.

8. The construction method according to claim 7, characterized in that: When pumping water, the water pump (9) is placed in the well pipe (1) to perform the pumping operation.

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