Energy-saving electrolytic desaturation spiral precast pile foundation and construction method thereof

Abstract

The application discloses an energy-saving electrolytic desaturation spiral precast pile foundation and a construction method thereof, and comprises a plurality of pile foundations, each of which comprises a first pile body and a second pile body, the first pile body is internally provided with the second pile body, the first pile body top and the second pile body top are connected through a torsion arm, the first pile body bottom and the second pile body bottom are provided with pile tips, and the pile tip tops of the pile foundations are respectively provided with ultrasonic wave emitters and ultrasonic wave receivers. The electrode arrangement of electrolytic desaturation can be completed while the pile foundation is constructed, the additional construction steps are reduced, the disturbance to the soil body in the traditional method is avoided, and the safety of the project is increased. When the spiral pile body is electrified, self-induction and mutual induction phenomena occur, the self-induction phenomenon can make the pile body still have current for electrolysis within a period of time after power-off, and the mutual induction phenomenon can make the surrounding pile without power also generate current, so that the electrolysis effect is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrolytic desaturation prefabricated pile foundation and a construction method thereof, in particular to an energy-saving electrolytic desaturation spiral prefabricated pile foundation and a construction method thereof. BACKGROUND

[0002] As a new type of saturated sand foundation treatment method, electrolytic desaturation has been proved to be superior through various tests. However, the traditional electrolytic method is realized through electrode plates, which requires drilling a large number of deep holes in the sand foundation, which not only easily causes disturbance to the soil body and reduces the strength of the soil body, but also requires long-time uninterrupted power supply to realize its function, and the energy consumption is high. Therefore, at present, it is necessary to study a sand electrolytic desaturation method which can reduce unnecessary disturbance to the soil body and has low energy consumption. SUMMARY

[0003] The purpose of the present application is to provide an energy-saving electrolytic desaturation spiral prefabricated pile foundation and a construction method thereof, which can reduce unnecessary disturbance to the soil body, and use the self-induction and mutual induction of the coil to reduce the electrolytic energy consumption, reduce the electrolytic cost and additional construction cost.

[0004] Technical scheme: The present application comprises a plurality of pile foundations, each pile foundation comprising a first pile body and a second pile body, the first pile body being internally provided with the second pile body, the first pile body top and the second pile body top being connected by a torsion arm, the first pile body bottom and the second pile body bottom being provided with a pile tip, the pile tip top of the spaced pile foundations being respectively provided with an ultrasonic wave transmitter and an ultrasonic wave receiver.

[0005] The first pile body is a spiral pile body, and the second pile body is a columnar pile body.

[0006] The circuit of the ultrasonic wave transmitter and the ultrasonic wave receiver is arranged around the spiral pile body, and conductive glue is smeared on the surface of the spiral pile body.

[0007] The surface of the conductive glue is smeared with a protective layer, which dissolves when it comes into contact with water, so that the conductive graphite glue is exposed to water and electrolysis can be carried out, and the dissolved matter has good conductivity, which can increase the electrolysis effect.

[0008] The conductive glue is connected to the control end.

[0009] The columnar pile body is made of metal material, and the surface of the columnar pile body is sprayed with waterproof paint to prevent rust in water.

[0010] The ultrasonic wave transmitter and the ultrasonic wave receiver are connected to the control end.

[0011] The pile tip is a concrete pile tip.

[0012] An energy-saving electrolytic desaturation spiral precast pile foundation construction method comprises the following steps:

[0013] (1) a spiral pile body is made, and the lines of an ultrasonic transmitter and an ultrasonic receiver are arranged around the spiral pile body, and then conductive glue is applied on the spiral surface;

[0014] (2) a protective layer is applied on the surface of the conductive glue;

[0015] (3) a columnar pile body and a torsion arm are made, waterproof paint is sprayed on the surface of the columnar pile body, and the spiral pile body, the columnar pile body and the torsion arm are connected;

[0016] (4) a pile tip is connected with the spiral pile body and the columnar pile body;

[0017] (5) the conductive glue and a control end are connected;

[0018] (6) the ultrasonic transmitter and the ultrasonic receiver are respectively placed on the pile tips of the pile foundations that are spaced apart, and are connected with the control end;

[0019] (7) a plurality of piles are sunk into the foundation;

[0020] (8) the relationship between the saturation of the soil and the ultrasonic propagation speed is obtained through indoor tests;

[0021] (9) if the saturation exceeds a predetermined value, the conductive glue is powered on through the control end, and the piles that are spaced apart are powered on, the piles are powered off after a period of time, and the piles that are not used before are powered on, the pore water is continuously electrolyzed, and the step is repeated, so that the saturation of the soil is maintained below the expected value.

[0022] Advantages:

[0023] (1) the spiral pile body and the columnar pile body are adopted, and the pile tip is provided, the piles are sunk in the mode of being twisted and pressed down, compared with traditional ramming pile sinking and static pressure pile sinking, the disturbance to the soil is smaller, the piles are easier to sink, the contact area of the spiral pile body with the soil is larger, the friction and the bearing capacity are larger, and the stability and the support of the piles are guaranteed;

[0024] (2) the spiral pile body can effectively reduce the soil squeezing effect in the pile sinking process, so that multiple constructions can be carried out in a short time, the spiral pile body is also beneficial to fixing the surrounding soil, so as to reduce the deformation of the soil and guarantee the safety of the project;

[0025] (3) the surface of the conductive graphite glue is covered with a polyacrylamide protective layer, the graphite glue can be protected from being damaged by sand particles in the pile sinking process, and the solution after dissolution also has high conductivity, and the electrolysis effect can be enhanced;

[0026] (4) The helical pile body of the present application can generate self-induction and mutual induction when energized, the self-induction can make the pile body still have current for electrolysis within a period of time after power-off; the mutual induction can make the piles not energized around also generate current, thereby realizing the electrolysis effect, and the iron cylindrical pile body can enhance the mutual induction effect, further reducing energy consumption;

[0027] (5) The helical pile body of the present application can decide whether to be reused according to engineering requirements, so as to reduce the engineering cost;

[0028] (6) The upper region of the pile tip of the present application is hollow, so that the ultrasonic transmitter and the ultrasonic receiver can be protected from being damaged during pile sinking, and when the soil body is subjected to dynamic load to generate uplift force, a larger resistance can be provided to prevent the movement of the pile and improve the safety of the foundation;

[0029] (7) The present application can complete the electrode arrangement for electrolytic desaturation while constructing the pile foundation, reduce the additional construction steps, and avoid the disturbance to the soil body in the traditional method, thereby increasing the safety of the project;

[0030] (8) The traditional resistance sensor can only measure the saturation of the soil body around the sensor, and cannot measure the saturation of a long distance, the present application can measure the saturation of the soil body between two piles through the propagation speed of ultrasonic waves, which is simple, fast and has no adverse effect on the soil foundation and building foundation. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 is the overall schematic diagram of the present application;

[0032] Fig. 2 is the single pile foundation schematic diagram of the present application;

[0033] Fig. 3 is the top view of the single pile foundation of the present application. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with the drawings.

[0035] As Figs. 1 to 3As shown, the present application comprises a plurality of pile foundations, each of which comprises a spiral pile body 5 and a columnar pile body 8, the columnar pile body 8 is arranged inside the spiral pile body 5, the top of the spiral pile body 5 and the top of the columnar pile body 8 are welded together through the torsion arm 4, and the bottom of the spiral pile body 5 and the bottom of the columnar pile body 8 are provided with a conical pile tip 10. Among them, the pile tip top of the pile foundation is respectively fixed with an ultrasonic transmitter 9 and an ultrasonic receiver 11, and the ultrasonic transmitter 9 and the ultrasonic receiver 11 are connected with the control end 1 through the line 3, and the control end 1 is used for power supply and ultrasonic data collection. The line 3 of the ultrasonic transmitter 9 and the ultrasonic receiver 11 is arranged around the spiral pile body 5, and then the surface of the spiral pile body 5 is uniformly coated with conductive graphite glue, and the conductive graphite glue is selected in this embodiment, and the appropriate thickness is selected according to the actual engineering situation, generally 1mm to 10mm, the spiral pile body 5 coated with conductive graphite glue is placed in an environment with a temperature of 30℃ for 24-36 hours, and then heated to 80℃ for 3-4 hours, and then heated to 120℃ for 3 hours, and finally cooled to solidify the graphite glue. The polyacrylamide dissolved at high temperature is coated on the surface of the conductive graphite glue to form a dense protective layer, and the protective layer should be determined according to the soil condition of the engineering site, and the thickness is generally kept at 5mm to 20mm, and if the sand particles are coarse and sharp, the protective layer can be appropriately increased. The protective layer dissolves when it comes into contact with water, so that the conductive graphite glue is exposed to water for electrolysis, and the dissolved material has good conductivity, which can increase the electrolysis effect.

[0036] The spiral pile body 5 is made of spring steel material, the total length of the pile body is 5-12 meters, the diameter is 1-3 meters, and the specific situation is determined, which can be appropriately increased. The upper part is provided with a support ring for welding treatment with the torsion arm 4 in the later period, the effective number of turns is 10-30, which can ensure the self-induction and mutual induction efficiency and quickly drill into the ground, and the spiral line diameter is 10mm-100mm. The carbon content of the steel should be kept at 0.6%-0.9%, the manganese content should be kept at 0.5%-0.8%, and the silicon content should be 1.5%-2%, and other metals such as chromium, nickel and copper can also be added according to the actual engineering needs, but the content should be kept low to avoid adverse effects on the pile body. And the pile body should adopt hot rolling process to facilitate subsequent spiral forming and welding. Then the spiral pile body is smoothed by sand blasting or powder spraying, and then dried, and then covered with a plastic layer to prevent adhesion of subsequent materials.

[0037] The cylindrical pile body 8 is a cylindrical pile body made of metal material. In this embodiment, iron material is used, the diameter is 0.5-2 meters, and the diameter is mainly determined according to the size of the spiral pile body 5 and the bearing requirement of the actual project, and the surface is sprayed with waterproof paint to prevent rust in water. The length of the cylindrical pile body 8 is 5.2-12.5 meters, which should be slightly longer than the spiral pile body 5, so as to connect the pile tip 10 subsequently. The material of the torsion arm 4 is iron or other metal, the length is the radius of the spiral coil minus the radius of the cylindrical pile body, and the thickness is 50-100 mm, which is determined according to the size of the torsion machine and the mechanical parameters required for pile sinking.

[0038] The pile tip 10 is a concrete pile tip, which is selected according to the actual engineering requirement, 15-30 parts of C40 or above type cement, 5-8 parts of high-strength ceramic particles, 3-5 parts of natural gravel and 5-7 parts of river sand. After uniform stirring, pour into the mold, at the same time, connect the spiral pile body 5 and the cylindrical pile body 8 with the pile tip 10, and after 8-10 hours of autoclave curing, transfer to the standard curing room for continuous curing for more than 28 days. After curing, the ultrasonic transmitter 9 and the ultrasonic receiver 11 are respectively placed on the top of the pile tip 10 of the pile foundation, and the line 3 is connected to the previously prepared line. Because the propagation speed of ultrasonic wave in different media is different, the soil saturation between the two pile foundations can be measured according to the propagation speed, which is simple and fast and has no adverse effect on the soil foundation and building foundation.

[0039] The prepared pile foundation is sunk into the foundation by the torsion machine, and after sinking completely, the line of the ultrasonic transmitter 9 and the ultrasonic receiver 11 is connected to the control end 1, and then the control end 1 and the conductive graphite glue are connected by the wire 2. It should be noted that the positive and negative electrodes are respectively connected to two different pile foundations. The control end 1 is composed of an adjustable constant voltage direct current power supply of LRS300 type, an UMS ultrasonic sound field system and a windows system, which can realize precise control of direct current voltage and current, achieve the purpose of precise control, and can monitor the propagation speed of ultrasonic wave in the foundation to deduce the saturation of a large range of soil, and then electrolyze the saturated soil according to the actual engineering requirement. During electrolysis, the pile foundations are electrified, the time is maintained at 10-120 seconds, then paused for 5-20 seconds, and then the pile foundations not electrified before are electrified, and so on until the soil saturation reaches the expected requirement. This method can not only ensure the purpose of saturation reduction, but also save energy by using self-induction and mutual induction of the coil.

[0040] An energy-saving electrolytic saturation reduction spiral prefabricated pile foundation construction method, comprising the following steps:

[0041] (1) A spiral pile body 5 made of spring steel is made by using a large spring winding machine.

[0042] (2)Smooth the surface of the spiral pile body 5 and let it dry. Cover the surface with a plastic sheet to prevent the subsequent material from sticking. Arrange the lines of the ultrasonic transmitter 9 and the ultrasonic receiver 11 around the spiral pile body 5. Then evenly apply the conductive graphite glue. Keep the temperature at 30℃ and let it stand for 24-36 hours. Then heat it to 80℃ and keep the temperature constant for 3-4 hours. Then heat it to 120℃ and keep the temperature constant for 3 hours. Finally, let it cool down.

[0043] (3) Apply the polyacrylamide dissolved at high temperature to the surface of the conductive graphite glue to form a dense protective layer.

[0044] (4) Make the iron columnar pile body 8 and the iron torsion arm 4. Spray waterproof paint on the surface of the columnar pile body 8. Connect the spiral pile body 5, the columnar pile body 8 and the torsion arm 4 by welding.

[0045] (5) Connect the concrete conical pile tip with the spiral pile body 5 and the columnar pile body 8.

[0046] (6) Connect the conductive graphite glue and the control end 1 through the wire 2.

[0047] (7) Place the ultrasonic transmitter 9 and the ultrasonic receiver 11 on the pile tips 10 that are separated by the pile foundation. Connect them through the wire 3 and the control end 1.

[0048] (8) Sink multiple piles into the saturated or high-moisture sand soil foundation by twisting and pressing down.

[0049] (9) Obtain the relationship between the saturation and the ultrasonic propagation velocity of the soil body through indoor tests.

[0050] (10) If the saturation exceeds the predetermined value, pass current to the conductive graphite glue through the control end 1. The current should be passed to one pile at a time. After a period of time, disconnect the current from the above-mentioned pile and pass the current to the pile that has not been used before. Continue to electrolyze the pore water to reduce the saturation of the soil body. Repeat this step to keep the saturation of the soil body below the expected value and save energy by using the self-induction and mutual induction of the coil. The self-induction phenomenon allows the pile body to still have current for electrolysis for a period of time after being disconnected; the mutual induction phenomenon allows the piles that are not connected to the current to also generate current, thereby achieving the electrolysis effect. The iron cylindrical pile body can enhance the mutual induction effect and further reduce energy consumption.

[0051] In order to realize the repeated use of the spiral pile body 5, after the pile foundation is sunk into the saturated or high-moisture sand soil foundation, the connection part of the spiral pile body 5 and the columnar pile body 8 can be cut off. The spiral pile body 5 is twisted in the opposite direction and pulled out of the soil body, realizing the repeated use. At this time, the conductive graphite glue continues to be left in the soil body for electrolysis to reduce the saturation.

Claims

1. A construction method for an energy-saving electrolytic desaturated spiral precast pile foundation, characterized in that, This energy-saving electrolytic desaturation spiral precast pile foundation includes multiple pile foundations, each pile foundation comprising a first pile body and a second pile body. The second pile body is located inside the first pile body. The tops of the first and second pile bodies are connected by a torsion arm. Pile tips are located at the bottoms of the first and second pile bodies. An ultrasonic transmitter and an ultrasonic receiver are respectively located at the top of the pile tips of pile foundations separated by another pile foundation. The specific construction method includes: (1) Make a spiral pile body, arrange the lines of the ultrasonic transmitter and ultrasonic receiver around the spiral pile body, and apply conductive adhesive to the spiral surface. (2) Apply a protective layer to the surface of the conductive adhesive; (3) Make columnar pile body and torsion arm, and spray waterproof paint on the surface of columnar pile body, and connect spiral pile body, columnar pile body and torsion arm; (4) Connect the pile tip to the spiral pile body and the columnar pile body; (5) Connect the conductive adhesive and the control terminal; (6) Place an ultrasonic transmitter and an ultrasonic receiver on the tips of the piles of the adjacent pile foundations and connect them to the control terminal. (7) Drive multiple piles into the foundation; (8) Obtain the relationship between soil saturation and ultrasonic wave propagation speed through indoor tests; (9) If the saturation exceeds the predetermined value, the conductive adhesive is energized through the control terminal, and the piles that are separated are energized. After a period of time, the above piles are de-energized, and the previously unused piles are energized. The pore water is continuously electrolyzed. This step is repeated to keep the saturation of the soil below the expected value.

2. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 1, characterized in that, The first pile body is a spiral pile body, and the second pile body is a columnar pile body.

3. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 2, characterized in that, After the lines of the ultrasonic transmitter and ultrasonic receiver are arranged around the spiral pile body, conductive adhesive is applied to the surface of the spiral pile body.

4. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 3, characterized in that, The conductive adhesive has a protective layer coated on its surface.

5. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 3, characterized in that, The conductive adhesive is connected to the control terminal.

6. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 2, characterized in that, The columnar pile body is made of metal and the surface of the columnar pile body is coated with waterproof paint.

7. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 5, characterized in that, The ultrasonic transmitter and ultrasonic receiver are connected to the control terminal.

8. The construction method of an energy-saving electrolytic desaturated spiral precast pile foundation according to claim 1, characterized in that, The pile tip is a concrete pile tip.

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