Construction process method of a collaborative anti-freezing and uplifting device for PHC pipe piles

Abstract

The present invention belongs to the technical field of frozen soil construction, and specifically relates to a construction process method of a PHC pipe pile collaborative anti-freezing and pulling device. The PHC pipe pile collaborative anti-freezing and pulling device includes a sliding system, a steel inner sleeve pile body, and a steel anti-pulling spiral skeleton. The sliding system includes hydrophobic medium coarse sand, a steel outer sleeve, and a rubber sealing ring. The construction process is as follows: 1. Level the site and carry out static pressure pile construction of PHC pipe piles; 2. Clean the holes of PHC pipe piles; 3. Press and twist the anti-pulling spiral skeleton; 4. Pour fine aggregate concrete into the pile holes of PHC pipe piles; 5. Excavate around the piles, install the sliding system, and finally backfill and compact the sand and soil. The process utilizes the steel anti-pulling spiral skeleton and the sliding structure at the lower part of the pile body main body to consume and resist a certain amount of freezing and pulling force, achieving the purpose of preventing the pile body from being frozen and pulled. It does not require additional energy such as electric energy and heat energy to slow down soil frost heave, meets the requirements of PHC pipe pile anti-freezing and pulling in cold regions in winter, and can be popularized in cold regions in winter.

Description

Technical Field

[0001] The present invention belongs to the technical field of frozen soil construction engineering, and particularly relates to a construction process method of a PHC pipe pile collaborative anti-freezing and uplifting device. Background Art

[0002] In recent years, as a national new energy industry, solar energy is an effective means to reduce the consumption of non-renewable energy by converting solar energy into heat energy or electrical energy. In some areas with high latitudes and low altitudes, such as Daqing City, Heilongjiang Province, the advantages of solar thermal resources are fully utilized to actively promote the centralized construction of photovoltaic power station projects. Although such areas are rich in solar thermal resources and suitable for the development of solar photovoltaic industries, they are cold and long in winter, and the foundation soil is prone to seasonal frost heave and thaw settlement. The frost damage of the foundation soil may cause the photovoltaic system support to tilt and loosen, seriously affecting the safety, stability and applicability of the photovoltaic power generation system.

[0003] Due to the serious frost damage problem of the photovoltaic PHC pipe pile foundation, targeted anti-freezing and uplifting measures need to be taken. Common measures include: structural method, replacement method and oily isolation method. The structural method mainly improves the vertical uplift bearing capacity of a single pile by increasing the buried depth of the pile into the soil, and relies on the side friction of the pile below the frozen soil layer to resist the uplift force generated by the frozen soil layer on the pile; the replacement method mainly replaces the frost-susceptible soil within a certain frozen depth around the pile with non-frost-susceptible soil or weakly frost-susceptible soil, thereby eliminating or reducing the frost heave force within the replacement range. The replacement material can be medium coarse sand, gravel, etc. The replacement range is generally taken as 0.2 m around the pile; the oily isolation method mainly weakens the frost heave effect by applying oily materials within a certain frozen depth around the pile. Commonly used oily materials mainly include modified asphalt, industrial vaseline, etc. The above measures have all achieved certain effects, but there are design defects such as high cost, difficult construction, weak applicability and environmental pollution to varying degrees. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a construction process method of a PHC pipe pile collaborative anti-freezing and uplifting device, which utilizes the steel anti-uplift spiral skeleton and the sliding structure at the lower part of the pile body main body to consume and resist a certain amount of uplift force, so as to achieve the purpose of preventing the pile body from freezing and uplifting. It is not necessary to consume extra energy such as electric energy and heat energy to slow down soil frost heave, which meets the requirements of PHC pipe pile anti-freezing and uplifting in cold regions in winter and can be popularized in cold regions in winter.

[0005] The technical solution adopted by the present invention is: a construction process method of a PHC pipe pile collaborative anti-freezing and uplifting device, the PHC pipe pile collaborative anti-freezing and uplifting device includes a sliding system, a steel inner sleeve pile body and a steel anti-uplift spiral skeleton, and the sliding system includes hydrophobic medium coarse sand, a steel outer sleeve and a rubber sealing ring;

[0006] The construction process method of the PHC pipe pile collaborative anti-freezing and uplifting device includes the following steps:

[0007] Step 1: Before the construction of PHC pipe pile driving, clear the ground, high altitude and underground obstacles within the scope of the pile foundation, level the site, and measure and set the points according to the points arranged in the drawings; lift the steel inner sleeve pile body by lifting tools, and drive the PHC pipe pile by a static pile driver. During the driving process, repeatedly measure the verticality and pile depth of the steel inner sleeve pile body to ensure that the verticality and pile depth meet the design requirements, and the pile depth is greater than the maximum freezing depth of the site, and at least 200 mm deeper than the maximum freezing depth;

[0008] Step 2: Use a disposable hole cleaning device to clean the PHC pile hole, so that the bottom of the steel inner sleeve pile body hole is flush with the bottom of the pile body, and the upper and lower errors do not exceed 200 mm. Clean the PHC pile hole. In the process of cleaning the hole after pile pressing, use the hole cleaning method of bored pile;

[0009] Step 3: Press and twist the steel anti-pullout spiral skeleton. During the process of pressing and twisting the steel anti-pullout spiral skeleton, the maximum diameter of the steel anti-pullout spiral skeleton used is 150 mm smaller than the inner diameter of the steel inner sleeve pile body. The steel anti-pullout spiral skeleton is pressed and twisted from the hole in the middle of the steel inner sleeve pile body by a self-propelled pile driver. During the pressing and twisting process, the verticality of the spiral skeleton must be ensured to meet the design requirements to avoid damage to the PHC pipe pile. The steel anti-pullout spiral skeleton is pressed until its top is 300 mm higher than the top of the pile body, so as to stop pressing the pile.

[0010] Step 4: After the pile is driven, the top of the steel anti-pulling spiral skeleton and the top of the steel inner sleeve pile body are supported by a mold. The mold is tubular, and the inner diameter of the mold is the same as the outer diameter of the steel inner sleeve pile body. The mold height is 300mm. Fine stone concrete is poured in the pile hole. After the fine stone concrete is completely solidified, the mold is removed, and the pile body is regularly maintained.

[0011] Step 5. After the pile installation construction is completed, the radius of the pile is 750 mm. The initial excavation is carried out mechanically using small excavation equipment. After the excavation is close to the bottom of the PHC pipe pile, the earth around the pile body is excavated manually. Avoid disturbing the pile body during the excavation process to ensure the verticality of the pile body; lay out the sliding system. Before laying out the sliding system, first fix the limit pins at the bottom of the steel inner sleeve, then install the rubber sealing ring and the steel outer sleeve, and fill the steel inner sleeve and the steel outer sleeve with hydrophobic medium-coarse sand, seal the upper part with a rubber sealing ring, and then fix the limit pins on the upper part of the steel inner sleeve; finally, use sand backfill, and vibrate and compact it to ensure the density of the backfill soil.

[0012] Furthermore, the limit pin is fixed on the steel outer sleeve by welding or punching.

[0013] Furthermore, the PHC pipe pile collaborative anti-freezing and anti-pulling device can be obtained through the construction process method of the described PHC pipe pile collaborative anti-freezing and anti-pulling device.

[0014] Furthermore, a steel anti-pulling spiral skeleton passes through the PHC pipe pile hole, and the spiral skeleton tip more than 500 mm is exposed at the lower part to prevent the pile body from being pulled out of the soil due to the anti-pulling force. The spiral skeleton tip is treated with galvanized anti-corrosion to avoid rust damage underground. The arrow part of the steel spiral skeleton exposed uses a spiral blade structure, and the upper part uses a thread structure.

[0015] Furthermore, the thickness of the external sliding steel sleeve is 5 mm, the surface is smooth, and the sleeve height is the same as the maximum frost depth of the site.

[0016] Furthermore, an internal steel sleeve with a thickness of 3 mm and a smooth surface is adopted on the outer side of the PHC pipe pile body. Anti-pulling spiral skeleton pressing and torsion construction is carried out inside the PHC pipe pile hole and fine stone concrete is poured for fixation.

[0017] Furthermore, the steel anti-pulling spiral skeleton is located inside the PHC pipe pile hole and is fixed as a whole with the PHC pipe pile by pouring fine stone concrete.

[0018] Furthermore, the steel outer sleeve and the steel inner sleeve pile body in the sliding system slide through the hydrophobic medium coarse sand to offset the tangential frost heaving force of the soil. The hydrophobic medium coarse sand has strong hydrophobicity, and the sand grains are processed by a silane reagent emulsion.

[0019] The beneficial effects of the present invention: The present invention provides a construction process method for a PHC pipe pile collaborative anti-freezing and anti-pulling device, which utilizes the anti-pulling spiral skeleton and the sliding structure at the lower part of the pile body to consume and resist the freezing and pulling force to achieve the purpose of preventing the pile body from freezing and pulling. Its main advantages are as follows:

[0020] (1) Utilize the sliding system to consume the tangential frost heaving force generated by the frozen soil on the pile side. The sliding movement of the steel sleeve in the sliding system consumes the tangential frost heaving force to improve the stability of the pile body, thereby avoiding the rise, settlement or inclination of the pile foundation due to soil frost damage;

[0021] (2) The sliding system is filled with hydrophobic medium coarse sand granular materials. During the day when the temperature is relatively high and at night when the ambient temperature is relatively low, the hydrophobic medium coarse sand is always not hydrophilic, so as to keep dry and in a granular state, continuously ensuring that the steel inner sleeve and the steel outer sleeve maintain a free sliding state. This device can improve the unstable phenomenon during the bearing force process of the photovoltaic support and ensure the stability of the pile body main body;

[0022] (3) Connect an anti - pull steel spiral skeleton at the bottom of the pile in the underground part to prevent the pile from being frozen and pulled out due to the frost heave of frozen soil, ensure the stability of the pile itself, and do not change the hydrothermal environment of the frozen soil;

[0023] (4) The structure form is simple, making full use of the material properties and the principle of the action of frost heave force. It does not require other thermal energy sources, can independently improve and eliminate the phenomenon of frost heave and thaw settlement of frozen soil, is convenient for construction, not prone to failure, has good stability, and low maintenance cost;

[0024] (5) The construction method is simple and convenient, with low technical requirements, little disturbance to the surrounding foundation soil, reliable quality, not prone to failure, good stability, good durability, and low construction and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the installation schematic diagram of the PHC pipe pile collaborative anti - freeze - pull - out device in Embodiment 1;

[0026] Figure 2 is the front - view structural schematic diagram of the pile body in Embodiment 1;

[0027] Figure 3 is the top - view structural schematic diagram of the pile body in Embodiment 1;

[0028] Figure 4 is the structural schematic diagram of the steel anti - pull spiral skeleton in Embodiment 1. EMBODIMENT EXAMPLE

[0029] Referring to each figure, a construction process method of a PHC pipe pile collaborative anti - freeze - pull - out device, the PHC pipe pile collaborative anti - freeze - pull - out device includes a sliding system, a steel inner sleeve pile body 3, and a steel anti - pull spiral skeleton 2. The sliding system includes hydrophobic medium - coarse sand 5, a steel outer sleeve 4, and a rubber sealing ring 6; a concrete pile body 1 is poured in the pile body; a photovoltaic support is arranged on the pile body, and a photovoltaic panel is arranged on the photovoltaic support.

[0030] The construction process method of the PHC pipe pile collaborative anti - freeze - pull - out device includes the following steps:

[0031] Step 1: Before the PHC pipe pile pressing construction, clean the ground, high - altitude, and underground obstacles within the scope of the pile foundation, level the site, and measure and set out the points according to the points arranged in the drawings; lift the steel inner sleeve pile body by a lifting tool, press the PHC pipe pile by a static pile press, and repeatedly measure the verticality and the pile - sinking depth of the steel inner sleeve pile body during the pile - pressing process to ensure that the verticality and the pile - sinking depth meet the design requirements, where the pile - sinking depth is greater than the maximum frost depth of the site and at least 200 mm deeper than the maximum frost depth;

[0032] Step 2: Use a one-time hole cleaning device to clean the holes of PHC pipe piles, making the bottom of the hole in the steel inner sleeve pile body flush with the bottom of the pile body, with an up-and-down error not exceeding 200 mm. Clean the holes of the PHC pipe piles. During the process of cleaning the holes after pile pressing, adopt the hole cleaning method of bored cast-in-place piles;

[0033] Step 3: Press and twist the steel anti-pull spiral skeleton. During the process of pressing and twisting the steel anti-pull spiral skeleton, the maximum diameter of the used steel anti-pull spiral skeleton is 150 mm smaller than the inner diameter of the steel inner sleeve pile body; Through the hole in the middle of the steel inner sleeve pile body, use a self-propelled pile driver to carry out pressing and twisting construction on the steel anti-pull spiral skeleton. During the pressing and twisting process, ensure that the verticality of the spiral skeleton meets the design requirements to avoid damaging the PHC pipe pile; Stop pile pressing when the top of the steel anti-pull spiral skeleton is 300 mm higher than the pile top of the pile body;

[0034] Step 4: After pile pressing is completed, formwork the top of the steel anti-pull spiral skeleton and the pile top of the steel inner sleeve pile body. The formwork is tubular, with an inner diameter the same as the outer diameter of the steel inner sleeve pile body and a height of 300 mm. Pour fine aggregate concrete into the pile hole. After the fine aggregate concrete is completely solidified, remove the formwork, and regularly maintain the pile body;

[0035] Step 5: After the pile body installation construction is completed, excavate the area with a radius of 750 mm around the pile. For the preliminary excavation, use small-scale excavation equipment for mechanical excavation. After excavating to near the bottom of the PHC pipe pile, manually excavate the soil around the pile body. During the excavation process, avoid disturbing the pile body and ensure the verticality of the pile body; Install a sliding system. Before installing the sliding system, first fix the limit pin 7 at the lower part of the steel inner sleeve, then install the rubber sealing ring and the steel outer sleeve, and fill hydrophobic medium coarse sand in the steel inner sleeve and the steel outer sleeve. Seal the upper part through the rubber sealing ring, and then fix the limit pin at the upper part of the steel inner sleeve; Finally, backfill with sandy soil and vibrate and compact it to ensure the compactness of the backfill soil.

[0036] The limit pin is fixed on the steel outer sleeve by welding or drilling; The PHC pipe pile collaborative anti-freezing and pulling device can be obtained through the construction process method of the PHC pipe pile collaborative anti-freezing and pulling device.

[0037] When the soil temperature drops and frost heaving occurs, the normal frost heaving force generated by the frost heaving of frozen soil around the pile is resisted by the steel outer sleeve. Under the action of frost heaving or thaw settlement of frozen soil, the hydrophobic medium coarse sand ensures relative slip between the steel outer sleeve and the inner sleeve to consume the tangential frost heaving force. The total length of the slip system is determined by the depth of frozen soil. The steel outer sleeve is 5 mm thick, the steel inner sleeve is 3 mm thick, and there is a gap of more than 15 mm between the inner and outer sleeves. The gap is filled with hydrophobic medium coarse sand, and the upper and lower ends are sealed with rubber sealing rings. The steel anti-pull spiral skeleton and the PHC pipe pile are cast into one body with fine aggregate concrete to form the main body of the pile. The outside of the pile body is a steel inner sleeve. The steel inner sleeve is not wrapped within 300 mm from the pile top to ensure the installation of the photovoltaic bracket. Limit pins are provided at the pile top and the pile bottom to prevent the excessive slip of the sleeve from causing the failure of the slip structure. During the installation of the device, the shallow soil around the anti-frost heaving PHC pipe pile needs to be replaced. Coarse-grained sand is used as the replacement soil around the pile to ensure full contact between the pile body and the sand, and to ensure that the frost heaving of frozen soil generates a lower frost heaving force on the pile body.

[0038] The main material of the pile body is a concrete cylinder. An anti-pull spiral skeleton is arranged inside to strengthen the anti-pull capacity of the pile body and improve its own strength at the same time. The outside of the concrete cylinder is wrapped with a steel cylinder. The top is a plain concrete column body, and the bottom is the tip of the anti-pull spiral skeleton; the slip system is composed of a steel cylinder wrapped outside the main body of the pile and filled with hydrophobic medium coarse sand. When the air temperature drops below zero, the soil around the pile freezes and heaves. The normal frost heaving force is resisted by the steel cylinder. At the same time, the tangential frost heaving force is consumed by the slip between the steel cylinder and the pile body. The anti-pull force is provided by the anti-pull spiral skeleton at the pile bottom to prevent the vertical displacement of the pile body.

[0039] The slip system is filled with hydrophobic medium coarse sand material. The hydrophobic medium coarse sand material is isolated from water to a certain extent and remains dry in both low-temperature and high-temperature environments, so as to maintain a non-frozen discrete state and maintain a free slip in a low-resistance state between the external steel sleeve and the main body of the pile, thereby consuming the tangential frost heaving force generated by the frost heaving of frozen soil on the PHC pipe pile body. The outside of the hydrophobic medium coarse sand is sleeved with a 5-mm-thick steel sleeve. The outer surface of the steel sleeve is smooth and has a high stiffness to resist the normal frost heaving force on the pile body when the soil around the pile freezes and heaves. An anti-pull spiral skeleton is provided at the lower part of the main body of the pile to prevent the vertical displacement of the main body of the pile. Through the present invention, the phenomena such as the rise and tilt of the PHC pipe pile due to frost heaving and thaw settlement are alleviated, which affects its use effect.

[0040] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A construction process method of a PHC pipe pile collaborative anti-freezing and uplifting device, characterized in that: The PHC pipe pile cooperative anti-freezing and pulling device comprises a sliding system, a steel inner sleeve pile body and a steel anti-pulling spiral skeleton, wherein the sliding system comprises hydrophobic medium-coarse sand, a steel outer sleeve and a rubber sealing ring; The construction process of the PHC pile cooperative anti-freezing and pulling device comprises the following steps: Step 1: Before the construction of PHC pile driving, clear the ground, high altitude and underground obstacles within the scope of the pile foundation, level the site, and measure and set the line points; lift the steel inner sleeve pile body by lifting tools, and drive the PHC pile by a static pile driver. During the driving process, repeatedly measure the verticality and pile depth of the steel inner sleeve pile body, where the pile depth is greater than the maximum freezing depth of the site; Step 2: Clean the hole of the PHC pile, make the bottom of the hole of the steel inner sleeve pile body flush with the bottom of the pile body, and the upper and lower errors do not exceed 200 mm, and clean the hole of the PHC pile; Step 3: compress and twist the steel anti-pullout spiral skeleton. During the compressing and twisting process, the maximum diameter of the steel anti-pullout spiral skeleton used is 150 mm smaller than the inner diameter of the steel inner sleeve pile body. The steel anti-pullout spiral skeleton is compressed and twisted from the hole in the middle of the steel inner sleeve pile body by a self-propelled pile driver. The pile pressing is stopped when the top of the steel anti-pullout spiral skeleton is 300 mm higher than the top of the pile body. Step 4: After the pile is driven, the top of the steel anti-pulling spiral skeleton and the top of the steel inner sleeve pile body are supported by a mold. The mold is tubular, and the inner diameter of the mold is the same as the outer diameter of the steel inner sleeve pile body. The mold height is 300mm. Fine stone concrete is poured in the pile hole. After the fine stone concrete is completely solidified, the mold is removed, and the pile body is regularly maintained. Step 5. After the pile installation construction is completed, the radius of the pile is 750 mm. The initial excavation is carried out mechanically using small excavation equipment. After the excavation is close to the bottom of the PHC pipe pile, the earth around the pile body is excavated manually. Avoid disturbing the pile body during the excavation process to ensure the verticality of the pile body; lay out the sliding system. Before laying out the sliding system, first fix the limit pins at the bottom of the steel inner sleeve, then install the rubber sealing ring and the steel outer sleeve, and fill the steel inner sleeve and the steel outer sleeve with hydrophobic medium-coarse sand, seal the upper part with a rubber sealing ring, and then fix the limit pins on the upper part of the steel inner sleeve; finally, use sand backfill, and vibrate and compact it to ensure the density of the backfill soil.

2. The construction process method of a PHC pipe pile collaborative anti-freezing and uplift device according to claim 1, characterized in that: The limit pin is fixed on the steel outer sleeve by welding or punching.

3. The construction process method of a PHC pipe pile collaborative anti-freezing and uplifting device according to claim 1 or 2, characterized in that: The PHC pipe pile coordinated anti-freezing and pulling device can be manufactured by the construction process method of the PHC pipe pile coordinated anti-freezing and pulling device.

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