Drainage Anti-slide pipe pile suitable for open channel project of expansive soil in cold and arid regions and construction method thereof

Abstract

A drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions and a construction method thereof are provided. The pipe pile includes a pile body, wherein the pile body is provided with a dewatering section and an embedded section arranged up and down, a wall of the dewatering section of the pile body is provided with a plurality of drainage channels for consolidation drainage; and the embedded section of the pile body is embedded in a solid rock stratum to provide an anti-slide effect. The drainage anti-slide pipe pile is more targeted at the expansive soil channel project in cold and arid regions, which can effectively control seepage water level behind a channel slope in an operational period, quickly reduces lagging dewatering level behind the slope in the initial stage of a shutdown period, and improves the stability of the entire slope.

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS

[0001] This application is based upon and claims priority to Chinese Patent Application No. 202410350399.X, filed on Mar. 26, 2024, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present invention belongs to the technical field of water conservancy project construction, and specifically relates to a drainage anti-slide ecological pipe pile suitable for an open channel project of expansive soil in cold and arid regions and a construction method thereof, which are suitable for preventing landslide disasters of expansive soil slopes in water conservancy project construction, and is particularly suitable for expansive soil slopes in cold and arid regions.BACKGROUND

[0003] The seasonal changes in Xinjiang region of China are very obvious: hot in summer, cold in winter, rapid temperature increase in spring, and rapid temperature decrease in autumn. Especially in northern Xinjiang, the adverse effects of climate factors on the construction, operation and maintenance of water conservancy project are more obvious. In the changing seasons of the year, after the end of summer, the shutdown period comes, the channel water level drops rapidly and eventually empties, the temperature drops rapidly in autumn and reaches the lowest in winter, and the operational period begins again in the middle of the following spring. Expansive soil channels located in cold and arid regions also experience significant dry-wet-freeze-thaw cycles under the influence of climate.

[0004] The instability failure mechanism of the expansive soil slope is as follows: during the annual operational period, the seepage water infiltrates the channel slope and makes the expansive soil saturated with water, showing an expansion trend; and with the end of the operational period, the seepage water level gradually decreases, and the shrinkage of the expansive soil due to water loss can easily lead to cracks in the shallow soil. However, due to the slow discharge of seepage water behind the channel slope and the rapid decrease in temperature during the shutdown period in autumn and winter, the seepage water still remained in the channel slope is easy to freeze into ice crystals, which further expands the soil body from the saturated state, destroys the original structure of the soil body, and reduces the strength of the soil body framework. Finally, before the end of winter and the beginning of the operational period in spring, the frozen ice crystals melt and are discharged in the form of seepage water, but the shallow and deep cracks in the soil body of the channel slope that have been caused cannot be repaired, and continue to develop in several cycles, eventually leading to the destruction of the channel slope structure. It can be seen from the failure mechanism that the slope problems induced by a dry-wet cycle, a freeze-thaw cycle, and a dry-wet-freeze-thaw cycle are all related to the water level of the seepage water behind the membrane, which is crucial to the control and drainage of the seepage water level behind the membrane for an open channel project. Although a box culvert water collection structure has been provided at the bottom of the channel for the seepage channel project behind the canal, the effect is poor. Therefore, there is a need for a drainage anti-slide ecological pile suitable for expansive soil slopes in cold and arid regions to solve the project problems and to greatly avoid the occurrence of shallow landslides and frost heave damage to expansive soil channels.

[0005] An anti-slide pile, as a retaining structure that has been widely used in slope anti-slide treatment for a long time, is the main measure for landslide control. The anti-slide pile is buried in the stable slide bed, transfer the landslide thrust to the stable stratum by relying on the mutual clamping effect between the piles and the rock (soil) around the piles, and stabilizes the landslide by the anchoring effect and anti-slide force of the pile body embedded in the stable rock stratum. After many scholars conducted targeted research and improvements on anti-slide piles, various types of drainage anti-slide piles were proposed. Compared with conventional anti-slide piles, drainage anti-slide piles have solved the problem of soil infiltration and drainage to a certain extent, while also retaining the landslide control function of anti-slide piles. Although different types of drainage anti-slide piles have been proposed and improved, most of which are based on composite foundation design. There is a lack of drainage anti-slide pile design suitable for open channel water transfer projects, and the problem of water seepage behind the slope is still an unresolved problem.SUMMARY

[0006] To overcome the defects in the prior art, the present invention provides a drainage anti-slide ecological pipe pile suitable for an open channel project of expansive soil in cold and arid regions and a construction method thereof, which can improve the stability of the channel slope by timely pumping out seepage water behind the channel slope to control the water level behind the slope.

[0007] To achieve the foregoing objective, the present invention adopts the following technical solutions.

[0008] A drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions includes a pile body, wherein the pile body is provided with a dewatering section and an embedded section arranged up and down, a wall of the dewatering section of the pile body is provided with a plurality of drainage channels for consolidation drainage; and the embedded section of the pile body is embedded in a solid rock stratum to provide an anti-slide effect.

[0009] Further, a pile cover is arranged on one side of the dewatering section of the pile body far away from the embedded section, so as to prevent soil particles from entering the interior of the pipe pile.

[0010] Further, the dewatering section, the embedded section and the pile cover of the pile body are all cast with steel slag concrete.

[0011] Further, a geomembrane is attached to an inner wall of the pile body.

[0012] Further, a water pumping channel is arranged at one end of the dewatering section of the pile body close to the embedded section.

[0013] Further, a ratio of the total area of the plurality of drainage channels to the side area of the pile body is less than 0.03; the plurality of drainage channels are arranged along the long direction of the pile body at a spacing of 0.5 m; and a diameter of the drainage channel is 1 / 10 of an outer diameter of the pile body.

[0014] Further, when arranged at the top of a channel slope, the drainage anti-slide pipe pile further includes an automatic water pumping and drainage device, the automatic water pumping and drainage device includes a water pumping and drainage pipe positioned in the pile body, one end of the water pumping and drainage pipe extends to the embedded section, and the other end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

[0015] Further, a plurality of water level sensors are arranged from top to bottom on an inner side wall of the dewatering section of the pile body, the plurality of water level sensors are electrically connected to a water level controller, and the water level controller is electrically connected to the water pump.

[0016] A construction method of a drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions is a construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions according to any one of the above aspects in the middle of a channel slope, and includes the following steps:

[0017] S110: performing on-site surveying and mapping, and determining a piling location and a length of a drainage anti-slide ecological pile according to the on-site water level and channel slope data during an operational period;

[0018] S120: according to the determined piling position, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at the bottom of the channel, then hoisting the pile to the drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pipe pile body to align with a construction hole, checking a verticality of the pipe pile body during the piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into the ground, starting to press the pile after the requirements are met, stopping the pile delivering when the embedded section is lowered to 1000 mm above the soil body, and completing the laying of a geomembrane on the inner wall of the pipe pile in advance before sinking the pipe pile;

[0019] S130: hoisting the dewatering section of the pipe pile body to the piling position, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking the verticality of the welded integral pile body, and completing the pile delivering process; and

[0020] S140: after the pile delivering process is completed, connecting a pre-buried drainage pipe with the hole of the dewatering section, pouring steel slag concrete into the pipe pile, and mounting the pile cover made of the steel slag concrete after the short pile is poured and cured.

[0021] A construction method of a drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions is a construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions according to any one of the above aspects in the top of a channel slope, and includes the following steps:

[0022] S210: performing on-site surveying and mapping, and determining a piling location and a length of a drainage anti-slide ecological pile according to the on-site water level and channel slope data during an operational period;

[0023] S220: arranging a water level sensor on the inner wall of the dewatering section of the pipe pile in advance before pile delivering, and connecting the other end of the sensor with the water level controller;

[0024] S230: according to the determined piling position, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at the bottom of the channel, then hoisting the pile to the drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pipe pile body to align with a construction hole, checking a verticality of the pipe pile body during the piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into the ground, starting to press the pile after the requirements are met, stopping the pile delivering when the embedded section is lowered to 1000 mm above the soil body;

[0025] S240: hoisting the dewatering section of the pipe pile body to the piling position, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking the verticality of the welded integral pile body, and completing the pile delivering process; and

[0026] S250: after the pile delivering process is completed, connecting a pre-buried drainage pipe with the hole of the dewatering section, pouring steel slag concrete into the pipe pile, and mounting the pile cover made of the steel slag concrete after the short pile is poured and cured. The beneficial effects of the present invention are as follows.

[0027] 1. Compared with the conventional drainage anti-slide pile, the present invention is more targeted at the expansive soil channel project in cold and arid regions, which can effectively control seepage water level behind a channel slope in an operational period, quickly reduces lagging dewatering level behind the slope in the initial stage of a shutdown period, and improves the stability of the entire slope.

[0028] 2. The concrete doped steel slag adopted by the drainage pipe pile of the present invention is a byproduct in the steel-making process, and the concrete doped steel slag is recycled to manufacture the drainage anti-slide pipe pile, so that the on-site environment-friendly disposal and recycling of steel slag waste are achieved, and the ecological protection effect is achieved.

[0029] 3. The automatic water pumping and drainage device adopted by the present invention is used to quickly reduce the lagging seepage water level behind the channel slope in the initial stage of a shutdown period, can also be used to control the seepage water level behind the channel slope in the operational period, which can greatly reduce the adverse effect of the seepage water behind the channel slope on the stability of the channel slope.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 is a front view of a pipe pile arranged in the middle of a channel slope according to the present invention;

[0031] FIG. 2 is a front view of a pipe pile arranged in the top of a channel slope according to the present invention;

[0032] FIG. 3 is a front view of an automatic water pumping and drainage device according to the present invention;

[0033] FIG. 4 is a schematic diagram of the location of a drainage anti-slide ecological pile in the middle of a channel slope according to the present invention;

[0034] FIG. 5 is a schematic diagram of the location of a drainage anti-slide ecological pile in the top of a channel slope according to the present invention; and

[0035] FIG. 6 is a schematic diagram of the overall layout design of the present invention on a channel slope.

[0036] In the drawings, 1: dewatering section; 2: embedded section; 3: pile body; 4: pile cover; 5: PVC drainage pipe; 6: geomembrane of dewatering section; 7: geomembrane of embedded section; 8: drainage channel; 9: water level sensor; 10: pile top water pumping port; 11: water pumping channel; 12: water pumping and drainage pipe; and 13: automatic water pumping and drainage device.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The present invention provides a drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions and a construction method thereof. The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings, so as to make the technical solutions easier to understand and grasp.Embodiment 1

[0038] Referring to FIGS. 1-6, a drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions includes a pile body 3, wherein the pile body 3 is provided with a dewatering section 1 and an embedded section 2 arranged up and down, a wall of the dewatering section 1 of the pile body 3 is provided with a plurality of drainage channels 8 for consolidation drainage; and the embedded section 2 of the pile body 3 is embedded in a solid rock stratum to provide an anti-slide effect.

[0039] In this embodiment, a pile cover 4 is arranged on one side of the dewatering section 1 of the pile body 3 far away from the embedded section 2, so as to prevent soil particles from entering the interior of the pipe pile.

[0040] In this embodiment, the dewatering section 1, the embedded section 2 and the pile cover 4 of the pile body 3 are all cast with steel slag concrete.

[0041] The dewatering section 1 and the embedded section 2 of the pile body 3 are welded into an integrated structure, wherein the length of the dewatering section 1 may be cut according to the actual working conditions of the channel.

[0042] Preferably, the connection between the dewatering section 1 and the embedded section 2 of the pile body 3 and the connection between the dewatering sections 1 are prefabricated with welding connectors.

[0043] The embedded section 2 of the pile body 3 is a short pile cast with steel slag concrete. The steel slag concrete is cast after the embedded section 2 is driven into the soil, and the entire pile body is embedded through the consolidation effect of the steel slag concrete during the pile forming process.

[0044] In this embodiment, steel slag concrete is used for casting, so that the problem of waste treatment in the production of a part of steel products is solved, and the ecological protection function is achieved.

[0045] In this embodiment, a geomembrane is attached to an inner wall of the pile body 3.

[0046] Specifically, the pile wall of the dewatering section 1 of the pile body 3 is attached with a geomembrane 6 of the dewatering section 1 close to the inner wall of the pile body 3, and the pile wall of the embedded section 2 of the pile body 3 is attached with a geomembrane 7 of the embedded section 2 close to the inner wall of the pipe pile, as so to prevent soil particles from flowing into the pile body 3.

[0047] In this embodiment, a water pumping channel 11 is arranged at one end of the dewatering section 1 of the pile body 3 close to the embedded section 2.

[0048] Specifically, a PVC drainage pipe 5 is provided on the water pumping channel 11.

[0049] In this embodiment, a ratio of the total area of the plurality of drainage channels 8 to the side area of the pile body 3 is less than 0.03; the plurality of drainage channels 8 are arranged along the long direction of the pile body 3 at a spacing of 0.5 m; and a diameter of the drainage channel 8 is 1 / 10 of an outer diameter of the pile body 3.

[0050] Specifically, the opening ratio of drainage channel 8 in the pile body should be limited according to the pile body bearing capacity requirements. The actual opening ratio value may be limited according to different actual project requirements, but it is recommended to be controlled within 3.0% based on construction experience, that is, the ratio of the total opening area to the side area of the pipe pile is controlled within 0.03. The opening diameter is reduced and the number of opening layers is increased under the condition of controlling the total opening area. The opening positions are evenly and symmetrically arranged along the pipe pile of the dewatering section 1. The drainage channel 8 is opened every 0.5 m along the pile length, that is, starting from the pile end, the channels are arranged in sequence along the pile length of 0.5 m, 1.0 m, 1.5 m, 2.0 m, and the like. According to construction experience, the opening diameter is selected as 1 / 10 of the outer diameter of the pipe pile, that is, the hole diameter is 100 mm.

[0051] The drainage anti-slide pipe piles provided by this embodiment are arranged at the top and the middle of the channel slope according to the drainage function and the setting position.

[0052] When the pipe pile is arranged in the middle of the channel slope, the water collected in the pipe piles is discharged into the box culvert at the bottom of the channel by gravity.

[0053] When arranged at the top of the channel slope, the drainage anti-slide pipe pile provided by this embodiment further includes an automatic water pumping and drainage device 13, the automatic water pumping and drainage device 13 includes a water pumping and drainage pipe 12 positioned in the pile body 3, one end of the water pumping and drainage pipe 12 extends to the embedded section 2, and the other end of the water pumping and drainage pipe extends to an outer side of the pile body 3 and is connected to a water pump; and the pumping and drainage is performed by the automatic water pumping and drainage device 13.

[0054] The pile cover 4 is provided with a pile top water pumping port 10 in advance for the water pumping and drainage pipe 12 to pass through.

[0055] A plurality of water level sensors 9 are arranged from top to bottom on an inner side wall of the dewatering section 1 of the pile body 3, the plurality of water level sensors 9 are electrically connected to a water level controller, and the water level controller is electrically connected to the water pump.

[0056] Specifically, the automatic water pumping and drainage device 13 can sense the water level in the pipe pile through the water level sensor 9, and automatically pump and drain after reaching the set drainage level, which can intelligently maintain the water level in the pipe pile so as to control the seepage water level behind the channel slope.

[0057] The water level sensor 9 may perform intelligent water level control according to the preset water level requirement. When the seepage water level behind the channel slope does not reach the designated water level, the water level controller does not work, and along with the rise of the seepage water level to the preset water level, the water level controller starts to control the water pump to drain water through the induction of the water level sensor 9, so that the water level is always kept below the preset water level.

[0058] According to the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions provided by this embodiment, when the drainage pipe pile is arranged at the top of the channel slope, water is collected in the pile body through the automatic water pumping and drainage device 13 and is not connected to a drainage pipe of a box culvert structure at the bottom of the channel.

[0059] When the drainage pipe pile is arranged in the middle of the channel slope, the automatic water pumping and drainage device 13 is not used for water pumping and drainage, and water collected in the pile body is collected to a drainage channel of a box culvert structure at the bottom of the channel through a PVC drainage pipe under the action of gravity.

[0060] The seepage water behind the channel slope enters the interior of the pipe pile through the drainage channel 8 on the side wall of the pile body 3 arranged in the middle of the channel slope, seeps downward inside the drainage pipe pile to the bottom of the dewatering section 1 and enters the box culvert structure at the bottom of the channel under the action of gravity, and is concentrated through the PVC drainage pipe 5 into the interior of the drainage pipe pile arranged at the top of the channel slope after the box culvert structure collects water to a certain extent. When the water level inside the pipe pile reaches the preset water level, the seepage water inside the pipe pile is pumped and drained to control the seepage water in the channel slope.Embodiment 2

[0061] The construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions provided by this embodiment is a construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions provided by Embodiment 1, wherein this construction method includes a construction method in the middle of a channel slope and a construction method in the top of a channel slope.

[0062] According to different setting positions, the construction methods of the pipe piles arranged at the middle and the top of the channel slope are described.

[0063] A construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions in the middle of a channel slope includes the following steps:

[0064] S110: performing on-site surveying and mapping, and determining a piling location and a length of a drainage anti-slide ecological pile according to the on-site water level and channel slope data during an operational period.S111: Site Leveling

[0065] General site treatment: obvious attachments on the surface of the site, such as plant roots, are removed. The soft areas in the site are compacted, especially the locations where pile foundation work is performed, to eliminate the adverse effects of the soft soil foundation.

[0066] Special waterlogged areas: for areas with temporary waterlogging due to factors such as rainfall, drainage or centralized pumping with water pumps shall be adopted to drain the water in the foundation pit and clean the site. The base is backfilled in layers and compacted gradually.S112: Pile Positioning Setting

[0067] The pipe pile construction is performed according to the construction section design and zoning design. The leveled site is measured and set, and the four outermost piling positions of each section are controlled as control points. The control points are precisely controlled and set using a total station or GPS.

[0068] S120: according to the determined piling position, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at the bottom of the channel, then hoisting the pile to the drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pipe pile body to align with a construction hole, checking a verticality of the pipe pile body during the piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into the ground, starting to press the pile after the requirements are met, stopping the pile delivering when the embedded section is lowered to 1000 mm above the soil body, and completing the laying of a geomembrane on the inner wall of the pipe pile in advance before sinking the pipe pile.S121: Pile Driver in Place

[0069] After debugging of all equipment is completed, the pile driver is put into place through the traveling device, and the load is not less than twice the design bearing capacity of a single pile.S122: Hoisting Prefabricated Pipe Pile in Place

[0070] Before the pipe pile is hoisted, the pile body size markings are set, one marking every 1000 mm, and a geomembrane is arranged on the inner wall of the pipe pile in advance. The pipe pile is hoisted vertically and transported to the pile clamp, the center of the pipe pile is controlled to align with the piling position, and the pipe pile is slowly pressed down to insert into the soil by about 500 mm.S123: Verticality Adjustment

[0071] The verticality of the pipe pile inserted into the pile position shall be checked and controlled to be no more than 0.5%.S124: Sinking the Dewatering Section Into the First Section of Prefabricated Pipe Pile

[0072] During the pile pressing process, the deviation of the pipe pile is observed at any time. If there is a serious problem, reconstruction should be performed. The deviation of the pile body should not be corrected forcibly, which may easily cause the pile body to break. The pile sinking construction must be slow within a depth of 5000 mm from the ground surface and after the pile end enters the bearing layer. The pile sinking speed in general stratum is controlled at 1500-2000 mm / min. When encountering hard interlayers or entering the bearing layer, the speed is controlled at 1000 mm / min. Otherwise, the pile head is prone to breakage due to too fast pile sinking.

[0073] S130: hoisting the dewatering section of the pipe pile body to the piling position, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking the verticality of the welded integral pile body, and completing the pile delivering process.S131: Pile Splicing

[0074] There are different designs according to the designed pile length and the number of pile sections in the dewatering section, but the pile splicing method is the same:

[0075] The upper prefabricated pipe pile and the lower prefabricated pipe pile are spliced by welding. To ensure the quality of the welding pile, the following steps are performed:

[0076] (1) Keeping the end surfaces of the upper pile section and the lower pile section flat, and positioning and fixing the periphery by spot welding;

[0077] (2) Removing impurities and oil stains on the end face;

[0078] (3) Aligning the end faces of the upper pile section and the lower pile section, keeping the upper pile section and the lower pile section straight, and controlling the dislocation deviation to be not more than 2 mm; and

[0079] (4) after the upper pile section and the lower pile section are fixed, symmetrically welding in layers. The welding seam must be full, and the defects of slag inclusion or air holes and the like cannot be generated. When pile splicing is performed, the height of the lower section of pile from the ground is reserved by about 1000 mm, after welding of each pile is completed, the pile is naturally cooled to the natural temperature, and the next step can only be performed after acceptance.S132: Final Pressing

[0080] The final pressing of the pipe pile construction is generally controlled by adopting double technical parameters, and the control method mainly adopts pipe pile length control as an auxiliary method and static pressure value control as a main method.

[0081] (1) The pile length meets the design requirements of the pipe pile, and the level is used to control the elevation of the pile top, and the deviation is controlled within ±50 mm.

[0082] (2) The final pressure meets the following conditions: twice the design bearing capacity of a single pile≤final pressure<the design ultimate bearing capacity of the pile.

[0083] S140: after the pile delivering process is completed, connecting a pre-buried drainage pipe with the hole of the dewatering section, and mounting the pile cover made of the steel slag concrete after the short pile is poured and cured.

[0084] It should be noted that: after the final pressure of the step S132 in the construction is completed, the drainage pipes laid in advance in the channel slope are connected to the drainage channels at the bottom of the dewatering section of the pipe pile to confirm that the water collected by the pipe piles can flow into the box culvert water collection structure at the bottom of the channel through the drainage pipes.

[0085] A construction method of the drainage anti-slide pipe pile suitable for the open channel project of expansive soil in cold and arid regions in the top of a channel slope includes the following steps:

[0086] S210: performing on-site surveying and mapping, and determining a piling location and a length of a drainage anti-slide ecological pile according to the on-site water level and channel slope data during an operational period.S211: Site Leveling

[0087] General site treatment: obvious attachments on the surface of the site, such as plant roots, are removed. The soft areas in the site are compacted, especially the locations where pile foundation work is performed, to eliminate the adverse effects of the soft soil foundation.

[0088] Special waterlogged areas: for areas with temporary waterlogging due to factors such as rainfall, drainage or centralized pumping with water pumps shall be adopted to drain the water in the foundation pit and clean the site. The base is backfilled in layers and compacted gradually.S212: Pile Positioning Setting

[0089] The pipe pile construction is performed according to the construction section design and zoning design. The leveled site is measured and set, and the four outermost piling positions of each section are controlled as control points. The control points are precisely controlled and set using a total station or GPS.

[0090] S220: arranging a water level sensor on the inner wall of the dewatering section of the pipe pile in advance before pile delivering, and connecting the other end of the sensor with the water level controller to ensure that the water level signal in the pile can be transmitted in time.

[0091] S230: according to the determined piling position, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at the bottom of the channel, then hoisting the pile to the drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pipe pile body to align with a construction hole, checking a verticality of the pipe pile body during the piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into the ground, starting to press the pile after the requirements are met, stopping the pile delivering when the embedded section is lowered to 1000 mm above the soil body.S231: Pile Driver in Place

[0092] After debugging of all equipment is completed, the pile driver is put into place through the traveling device, and the load is not less than twice the design bearing capacity of a single pile.S232: Hoisting Prefabricated Pipe Pile in Place

[0093] Before the pipe pile is hoisted, the pile body size markings are set, one marking every 1000 mm, and a geomembrane is arranged on the inner wall of the pipe pile in advance. The pipe pile is hoisted vertically and transported to the pile clamp, the center of the pipe pile is controlled to align with the piling position, and the pipe pile is slowly pressed down to insert into the soil by about 500 mm.S233: Verticality Adjustment

[0094] The verticality of the pipe pile inserted into the pile position shall be checked and controlled to be no more than 0.5%.S234: Sinking the Dewatering Section Into the First Section of Prefabricated Pipe Pile

[0095] During the pile pressing process, the deviation of the pipe pile is observed at any time. If there is a serious problem, reconstruction should be performed. The deviation of the pile body should not be corrected forcibly, which may easily cause the pile body to break. The pile sinking construction must be slow within a depth of 5000 mm from the ground surface and after the pile end enters the bearing layer. The pile sinking speed in general stratum is controlled at 1500-2000 mm / min. When encountering hard interlayers or entering the bearing layer, the speed is controlled at 1000 mm / min. Otherwise, the pile head is prone to breakage due to too fast pile sinking.

[0096] S240: hoisting the dewatering section of the pipe pile body to the piling position, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking the verticality of the welded integral pile body, and completing the pile delivering process.S241: Pile Splicing

[0097] There are different designs according to the designed pile length and the number of pile sections in the dewatering section, but the pile splicing method is the same:

[0098] The upper prefabricated pipe pile and the lower prefabricated pipe pile are spliced by welding. To ensure the quality of the welding pile, the following steps are performed:

[0099] (1) Keeping the end surfaces of the upper pile section and the lower pile section flat, and positioning and fixing the periphery by spot welding;

[0100] (2) Removing impurities and oil stains on the end face;

[0101] (3) Aligning the end faces of the upper pile section and the lower pile section, keeping the upper pile section and the lower pile section straight, and controlling the dislocation deviation to be not more than 2 mm; and

[0102] (4) after the upper pile section and the lower pile section are fixed, symmetrically welding in layers. The welding seam must be full, and the defects of slag inclusion or air holes and the like cannot be generated. When pile splicing is performed, the height of the lower section of pile from the ground is reserved by about 1000 mm, after welding of each pile is completed, the pile is naturally cooled to the natural temperature, and the next step can only be performed after acceptance.S242: Final Pressing

[0103] The final pressing of the pipe pile construction is generally controlled by adopting double technical parameters, and the control method mainly adopts pipe pile length control as an auxiliary method and static pressure value control as a main method.

[0104] (1) The pile length meets the design requirements of the pipe pile, and the level is used to control the elevation of the pile top, and the deviation is controlled within ±50 mm.

[0105] (2) The final pressure meets the following conditions: twice the design bearing capacity of a single pile≤final pressure<the design ultimate bearing capacity of the pile.

[0106] S250: after the pile delivering process is completed, connecting a pre-buried drainage pipe with the hole of the dewatering section, and mounting the pile cover made of the steel slag concrete after the short pile is poured and cured.

[0107] It should be noted that, in the process of the pile splicing in the step S241, a water level sensor is arranged on the inner wall of the dewatering section of the pipe pile, and the other end of the dewatering section of the pipe pile is connected with a monitoring device placed on a road on the top of the channel, so that a water level signal in the pipe pile can be transmitted in time.

[0108] After the final pressing in the step S242 is completed, the drainage pipe laid in advance in the channel slope is connected to the drainage channel at the bottom of the dewatering section of the pipe pile, and after the water is collected by the box culvert structure at the bottom of the channel and enters the interior of the pipe pile under the action of gravity, the water level sensor can reflect the water level change in time and start pumping and drainage after the set water level is reached.

[0109] The technical solutions of the present invention have been fully described above. It should be noted that the embodiments of the present invention are not limited by the above description, and all technical solutions formed by those of ordinary skill in the art in terms of structures, methods, or functions using equivalent transformations or equivalent variations according to the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A drainage anti-slide pipe pile suitable for an open channel project of expansive soil in cold and arid regions, comprising a pile body, wherein the pile body is provided with a dewatering section and an embedded section arranged up and down, a wall of the dewatering section of the pile body is provided with a plurality of drainage channels for consolidation drainage; and the embedded section of the pile body is embedded in a solid rock stratum to provide an anti-slide effect.

2. The drainage anti-slide pipe pile according to claim 1, wherein a pile cover is arranged on a side of the dewatering section of the pile body far away from the embedded section to prevent soil particles from entering an interior of the drainage anti-slide pipe pile.

3. The drainage anti-slide pipe pile according to claim 2, wherein the dewatering section, the embedded section, and the pile cover of the pile body are all cast with steel slag concrete.

4. The drainage anti-slide pipe pile according to claim 1, wherein a geomembrane is attached to an inner wall of the pile body.

5. The drainage anti-slide pipe pile according to claim 1, wherein a water pumping channel is arranged at an end of the dewatering section of the pile body adjacent to the embedded section.

6. The drainage anti-slide pipe pile according to claim 1, wherein a ratio of a total area of the plurality of drainage channels to a side area of the pile body is less than 0.03; the plurality of drainage channels are arranged along a long direction of the pile body at a spacing of 0.5 m; and a diameter of each of the plurality of drainage channels is 1 / 10 of an outer diameter of the pile body.

7. The drainage anti-slide pipe pile according to claim 1, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

8. The drainage anti-slide pipe pile according to claim 7, wherein a plurality of water level sensors are arranged from top to bottom on an inner side wall of the dewatering section of the pile body, the plurality of water level sensors are electrically connected to a water level controller, and the water level controller is electrically connected to the water pump.

9. A construction method of the drainage anti-slide pipe pile according to claim 1 in a middle of a channel slope, comprising the following steps:S110: performing on-site surveying and mapping, and determining a piling location and a length of the drainage anti-slide pipe pile according to on-site water level and channel slope data during an operational period;S120: according to the piling location, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at a bottom of the channel slope, then hoisting the drainage anti-slide pipe pile to a drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pile body to align with a construction hole, checking a verticality of the pile body during a piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into ground, starting to press the drainage anti-slide pipe pile after requirements are met, stopping pile delivering when the embedded section is lowered to 1000 mm above a soil body, and completing laying of a geomembrane on an inner wall of the drainage anti-slide pipe pile in advance before sinking the drainage anti-slide pipe pile;S130: hoisting the dewatering section of the pile body to the piling location, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking a verticality of a welded integral pile body, and completing a pile delivering process; andS140: after the pile delivering process is completed, connecting a pre-buried drainage pipe with a hole of the dewatering section, pouring steel slag concrete into the drainage anti-slide pipe pile, and mounting a pile cover made of the steel slag concrete after a pouring and a curing are completed.

10. A construction method of the drainage anti-slide pipe pile according to claim 1 at a top of a channel slope, comprising the following steps:S210: performing on-site surveying and mapping, and determining a piling location and a length of the drainage anti-slide pipe pile according to on-site water level and channel slope data during an operational period;S220: arranging a water level sensor on an inner wall of the dewatering section of the pile body in advance before pile delivering, and connecting an end of the water level sensor with a water level controller;S230: according to the piling location, drilling a hole by rotary drilling, the hole extending to a water pumping pipe of a box culvert structure at a bottom of the channel slope, then hoisting the drainage anti-slide pipe pile to a drilling position, slowly piling, lowering the embedded section and the dewatering section of the pile body in sections, hoisting the embedded section of the pile body to align with a construction hole, checking a verticality of the pile body during a piling process, controlling a vertical deviation to be less than or equal to 0.5% when a first section of the pile body and the embedded section are inserted into ground, starting to press the drainage anti-slide pipe pile after requirements are met, stopping pile delivering when the embedded section is lowered to 1000 mm above a soil body;S240: hoisting the dewatering section of the pile body to the piling location, welding the dewatering section and the embedded section into an integral structure after checking the verticality of the pile body, checking a verticality of a welded integral pile body, and completing a pile delivering process; andS250: after the pile delivering process is completed, connecting a pre-buried drainage pipe with a hole of the dewatering section, pouring steel slag concrete into the drainage anti-slide pipe pile, and mounting a pile cover made of the steel slag concrete after a pouring and a curing are completed.

11. The drainage anti-slide pipe pile according to claim 2, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

12. The drainage anti-slide pipe pile according to claim 3, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

13. The drainage anti-slide pipe pile according to claim 4, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

14. The drainage anti-slide pipe pile according to claim 5, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

15. The drainage anti-slide pipe pile according to claim 6, wherein when arranged at a top of a channel slope, the drainage anti-slide pipe pile further comprises an automatic water pumping and drainage device, the automatic water pumping and drainage device comprises a water pumping and drainage pipe positioned in the pile body, a first end of the water pumping and drainage pipe extends to the embedded section, and a second end of the water pumping and drainage pipe extends to an outer side of the pile body and is connected to a water pump.

16. The construction method according to claim 9, wherein in the drainage anti-slide pipe pile, the pile cover is arranged on a side of the dewatering section of the pile body far away from the embedded section to prevent soil particles from entering an interior of the drainage anti-slide pipe pile.

17. The construction method according to claim 16, wherein in the drainage anti-slide pipe pile, the dewatering section, the embedded section, and the pile cover of the pile body are all cast with the steel slag concrete.

18. The construction method according to claim 9, wherein in the drainage anti-slide pipe pile, the geomembrane is attached to an inner wall of the pile body.

19. The construction method according to claim 9, wherein in the drainage anti-slide pipe pile, a water pumping channel is arranged at an end of the dewatering section of the pile body adjacent to the embedded section.

20. The construction method according to claim 9, wherein in the drainage anti-slide pipe pile, a ratio of a total area of the plurality of drainage channels to a side area of the pile body is less than 0.03; the plurality of drainage channels are arranged along a long direction of the pile body at a spacing of 0.5 m; and a diameter of the drainage channel is 1 / 10 of an outer diameter of the pile body.

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