A layered grouting device and its application

Abstract

The invention discloses a layered grouting device and its application, and relates to a grouting pipe, comprising a grouting pipe, wherein a plurality of slurry outlet holes are formed on the side wall of the grouting pipe, a slurry supply pipe is formed in the grouting pipe, two cylindrical slurry stop plugs fixedly connected to the slurry supply pipe are sleeved on the outer wall of the bottom end of the slurry supply pipe from top to bottom, a slurry outlet space is provided between the two slurry stop plugs, slurry supply holes are formed on the tube body of the slurry supply pipe in the slurry outlet space, each of the slurry stop plugs is composed of an external shell and an internal elastic sealing cavity, a plurality of annular notches are uniformly formed on the side wall of the external shell from top to bottom, the outer wall of the internal elastic sealing cavity is fitted with the inner wall of the external shell, the two internal elastic sealing cavities are connected by a connecting pipe, and the upper internal elastic sealing cavity is also connected to an external pressure supply device by an air supply pipe; the invention can effectively achieve the purpose of layered grouting, and the grouting sequence can be flexibly set, thus avoiding the defects of traditional layered grouting.

Description

Technical Field

[0001] The invention relates to a grouting pipe, in particular to a device used for layered grouting. Background Art

[0002] Grouting pipe is a commonly used equipment in infrastructure construction. It opens a grouting hole on the pipe and injects grout into the pipe by an external grouting device. However, the traditional grouting method does not have an ideal grouting effect. Because the pipes are straight, the grout will flow autonomously to the grouting holes with high porosity in the surrounding soil, while the grouting amount of other parts that need to be filled cannot meet the requirements, which directly affects the grouting effect and increases the grouting cost.

[0003] The technical solution of partial layered grouting in the prior art adopts regional or segmented grouting, which can only grout from bottom to top, has poor flexibility, poor sealing effect, and overflow, which is not conducive to saving grouting costs. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a layered grouting device to solve the technical problem of poor layered grouting effect in the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] A layered grouting device comprises a grouting pipe, a plurality of slurry outlet holes are opened on the side wall of the grouting pipe from top to bottom, a slurry supply pipe whose top end is connected to an external grouting device and whose bottom end is closed is arranged in the grouting pipe, two cylindrical slurry stop plugs fixedly connected to the slurry supply pipe are sleeved on the outer wall of the bottom end of the slurry supply pipe from top to bottom, and the outer diameter of the slurry stop plugs is smaller than the inner diameter of the grouting pipe, a slurry outlet space is arranged between the two slurry stop plugs, slurry supply holes are opened on the tube body of the slurry supply pipe in the slurry outlet space, each of the slurry stop plugs is composed of an external shell and an internal elastic sealing cavity, a plurality of annular notches are evenly opened on the side wall of the external shell in the vertical direction from top to bottom, the outer wall of the internal elastic sealing cavity is in contact with the inner wall of the external shell, the two internal elastic sealing cavities are connected by a connecting pipe, and the internal elastic sealing cavity at the top is also connected to the external pressure supply device by an air supply pipe.

[0007] Furthermore, an oil supply pipe connected to an external oil supply device is also provided in the grouting pipe, and the bottom end of the oil supply pipe passes through the upper slurry stop plug and is fixedly connected to the top of the lower slurry stop plug. A first oil outlet hole is opened on the oil supply pipe above the upper slurry stop plug, and a second oil outlet hole is opened on the oil supply pipe between the two slurry stop plugs.

[0008] Furthermore, the outer wall of the grouting pipe where each slurry outlet hole is located is also connected to an annular slurry outlet pipe that wraps the grouting pipe, and overflow holes are evenly opened on the annular slurry outlet pipe.

[0009] Furthermore, the outer shell is specifically composed of a coaxially distributed upper cover, multiple middle support layers and a lower cover, all of which are sleeved on the slurry supply pipe and threadedly connected to its outer wall, the upper cover is specifically composed of a first transverse circular plate and a first annular vertical enclosure that is integrated with the first transverse circular plate and arranged at the bottom of its outer edge, the middle support layer is specifically composed of a cylindrical cavity and a second annular vertical enclosure that is arranged at the outer edge of the top end and the outer edge of the bottom end of the cylindrical cavity, the lower cover is specifically composed of a second transverse circular plate and a third annular vertical enclosure that is integrated with the second transverse circular plate and arranged at the top of its outer edge, the inner and outer diameters of all the annular vertical enclosures are the same, the internal elastic sealing cavity is specifically composed of multiple sleeves on the slurry supply pipe and the outer The inner diameter of the first annular vertical enclosure is composed of a cylindrical elastic sealing cavity, a cylindrical elastic sealing cavity is arranged between the upper cover and the adjacent middle supporting layer, between two adjacent middle supporting layers and between the lower cover and the adjacent middle supporting layer respectively, the distance between the bottom of the upper cover and the top of the adjacent middle supporting layer, the distance between the adjacent middle supporting layers and the distance between the top of the lower cover and the bottom of the adjacent middle supporting layer are the same as the thickness of the cylindrical elastic sealing cavity, two adjacent cylindrical elastic sealing cavities in the same slurry stop plug are connected by a high-pressure pipe, two adjacent cylindrical elastic sealing cavities in two slurry stop plugs are connected by a connecting pipe, and the cylindrical elastic sealing cavity at the top is connected to the external air supply pipe.

[0010] Furthermore, the first transverse circular plate is replaced by an upwardly convex arc-shaped plate.

[0011] Furthermore, the exposed edge of each annular enclosure is arc-shaped.

[0012] Furthermore, a one-way check device installed in the corresponding annular slurry outlet pipe is provided on the outer wall of the grouting pipe corresponding to each of the slurry outlet holes.

[0013] Furthermore, the connecting pipe is eliminated, and a pressure valve is fixedly installed on each high-pressure pipe. The pressure required for the cylindrical elastic sealing cavity to expand to contact the inner wall of the grouting pipe is less than the pressure required to open the pressure valve. Two branch pipes are provided at the bottom of the external air supply pipe, and each branch pipe is connected to the cylindrical elastic sealing cavity at the bottom of a grouting plug.

[0014] Furthermore, the grouting pipe and the annular grouting pipe are both fixedly installed in the steel cage.

[0015] The present invention also provides a method for performing layered grouting using the above-mentioned layered grouting device, the method comprising the following steps:

[0016] Step 1, after placing the above-mentioned layered grouting device as a whole into the bored pile hole, conventional bored pile is carried out to form a pile body;

[0017] Step 2: lower the slurry supply pipe and two slurry stoppers from the top of the grouting pipe into the grouting pipe until the target slurry outlet hole is in the slurry outlet space and then stop at the bottom, fixing the top of the slurry supply pipe;

[0018] Step 3: The external pressure supply device inputs high-pressure air into the air supply pipe, and the high-pressure air enters the cylindrical elastic sealing cavity at the bottom of each grouting plug through two branch pipes. When the corresponding cylindrical elastic sealing cavity expands to contact the inner wall of the grouting pipe and the pressure valve is not opened, the air supply is stopped;

[0019] Step 4: Open the external oil supply device to discharge oil to the top of each stop plug through the oil supply pipe via the first oil outlet hole and the second oil outlet hole. After the oil level overflows the top of each stop plug, stop supplying oil and open the external pressure supply device again.

[0020] Step 5: Make the pressure in each cylindrical elastic sealing cavity greater than the opening pressure of the pressure valve above it, so that each cylindrical elastic sealing cavity expands to fit closely with the inner wall of the grouting pipe, and close the external pressure supply device after the pressure in each cylindrical elastic sealing cavity is greater than the grouting pressure of the slurry;

[0021] Step 6: The external grouting device supplies slurry into the slurry supply pipe, and the slurry flows into the slurry outlet space through the slurry supply hole, flows into the annular slurry outlet pipe through the slurry outlet hole and the one-way check device, and overflows through the overflow hole for grouting until the grouting amount reaches the target grouting amount;

[0022] Step 7: After the grouting is completed, the external pressure supply device generates negative pressure, extracts the air in each cylindrical elastic sealing cavity and shrinks it into the corresponding grout stopper, and then pulls the grout supply pipe and the two grout stoppers together to the next grout outlet hole;

[0023] Step 8: Repeat steps 1-7 until all grouting holes are grouted.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The present invention uses two slurry stoppers to block the upper and lower sides of the slurry outlet hole, so that the slurry can only flow out from the designated slurry outlet hole, thereby effectively achieving the purpose of fixed-point layered grouting, and having strong flexibility;

[0026] 2. The present invention provides a slurry stopper as a combination of an external shell and an internal elastic sealing cavity, so that the slurry stopper forms a multi-layer seal when sealing, thereby effectively improving the sealing effect;

[0027] 3. The present invention can effectively avoid the influence of the consolidation slurry on the sealing effect by setting up an oil seal system, forming an oil seal layer and improving the sealing effect;

[0028] 4. The present invention realizes effective protection of the cylindrical elastic sealing cavity and improves the service life of the equipment by providing an oil supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the working state of the device in Example 1;

[0030] Figure 2 It is a cross-sectional top view of the connection between the grouting pipe and the annular slurry outlet pipe in Example 1;

[0031] Figure 3 It is a cross-sectional view of the internal elastic sealing cavity when the two slurry stop plugs in the first embodiment are working and not expanding;

[0032] Figure 4 It is a cross-sectional view of the expansion state of the internal elastic sealing cavity when the two slurry stop plugs in the first embodiment are working;

[0033] Figure 5 It is a cross-sectional view of the expansion state of the internal elastic sealing cavity when the two slurry stop plugs in the second embodiment are working;

[0034] Figure 6 It is a cross-sectional view of the expansion state of the internal elastic sealing cavity when the two slurry stop plugs in Example 3 are working.

[0035] In the figure: 1. grouting pipe; 2. slurry outlet hole; 3. slurry supply pipe; 4. slurry stopper; 5. slurry supply hole; 6. external shell; 7. internal elastic sealing cavity; 8. annular notch; 9. connecting pipe; 10. air supply pipe; 11. oil supply pipe; 12. first oil outlet hole; 13. second oil outlet hole; 14. annular slurry outlet pipe; 15. overflow hole; 16. upper cover; 17. middle support layer; 18. lower cover; 19. first horizontal circular plate; 20. first annular vertical enclosure; 21. cylindrical cavity; 22. second annular vertical enclosure; 23. second horizontal circular plate; 24. third annular vertical enclosure; 25. cylindrical elastic sealing cavity; 26. high-pressure pipe; 27. one-way check device; 28. pressure valve; 29. ​​support frame; 30. branch pipe. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] An embodiment of the present invention is described below: Example

[0038] Combination Figure 1-4The present embodiment provides a layered grouting device, including a grouting pipe 1. Similar to a conventional grouting pipe 1, a plurality of grouting holes 2 are provided on the side wall of the grouting pipe 1 from top to bottom in order to enable grouting at different heights. The positions of the grouting holes 2 on the grouting pipe 1 are the same as the positions where grouting is required. In order to avoid the defect that the grouting effect cannot be achieved in some positions due to the grouting of the grouting pipe 1 through the grouting holes 2 at the same time, it is necessary to meet the requirement that grouting can be performed on one grouting hole 2 alone while the other grouting holes 2 are not grouted.

[0039] In order to meet the above requirements, in this embodiment, first, a grouting supply pipe 3 with an outer diameter smaller than the inner diameter of the grouting pipe 1 is provided in the grouting pipe 1, and the grouting pipe 1 body is not used as a pipe for the slurry to flow in. Two cylindrical slurry stopping plugs 4 are fixedly installed at the bottom end of the slurry supply pipe 3, and their outer diameters are smaller than the inner diameter of the grouting pipe 1, so that they can move up and down in the grouting pipe 1 with the slurry supply pipe 3. The purpose of setting the slurry stopping plugs 4 is to block the grouting pipes 1 on the upper and lower sides of a slurry outlet hole 2 when grouting the slurry outlet hole 2, so that the slurry can only flow out of the slurry outlet hole 2 at that location. Therefore, the two slurry stopping plugs 4 do not contact each other, and a slurry outlet space is formed between the two. At the same time, they are in the two A slurry supply hole 5 is opened on the slurry supply pipe 3 between the two, and the bottom end of the slurry supply pipe 3 is closed. At the same time, due to the outer diameter of the slurry stopper 4 being smaller than the inner diameter of the grouting pipe 1, there is a gap between the two, and the slurry may be exposed through the gap and cannot enter the designated slurry outlet hole 2. Therefore, in this embodiment, the slurry stopper 4 is configured to be composed of a cylindrical outer shell 6 and an internal elastic sealing cavity 7, wherein the outer shell 6 is made of hard materials such as steel to form a supporting and protective effect, and a plurality of annular notches 8 are evenly opened from top to bottom on its vertical annular side wall, and the vertical direction enclosure formed by the plurality of annular notches 8 is connected to the top and bottom or the slurry supply pipe 3 to form a The outer shell 6 is a kind of internal elastic sealing cavity 7, which is made of elastic materials such as rubber and can be effectively expanded and contracted. Its shape is the same as the inner shape of the outer shell 6, so that it can be effectively accommodated in the outer shell 6. When high-pressure gas is injected into it, it expands. Due to the structure of the outer shell 6, its expanded part can only expand outwards from the annular notch 8, thereby effectively extruding with the inner wall of the grouting pipe 1. Pressure contact, because it is between the top and bottom ends of the outer shell 6, it must first fill the outside of the corresponding annular notch 8 and then expand to both sides. After the corresponding pressure is reached inside, on the one hand, it can effectively fix the relative position between the grouting plug 4 and the grouting pipe 1, and on the other hand, it can effectively seal the gap between the two, thereby achieving effective sealing. In particular, in order to achieve synchronous expansion of the two internal elastic sealing cavities 7 in the two grouting plugs 4, the two internal elastic sealing cavities 7 are connected by a connecting pipe 9, and the upper internal elastic sealing cavity 7 is connected to the external pressure supply device through an air supply pipe 10, thereby achieving the purpose of synchronous injection and pressure of the two.

[0040] Working principle of the equipment:

[0041] After the equipment is assembled, the whole consisting of the slurry discharge pipe and the two slurry stop plugs 4 is lowered from the top of the grouting pipe 1 into the inside thereof. During this process, the internal elastic sealing cavity 7 does not expand, so it can descend smoothly. When the slurry supply hole 5 on the slurry supply pipe 3 is at the same horizontal position as the slurry discharge hole 2 that needs grouting, that is, when the slurry discharge hole 2 is in the slurry discharge space, the external pressure supply device, i.e., an air pump, supplies high-pressure gas to the two internal elastic sealing cavities 7 through the air supply pipe 10, and then the two internal elastic sealing cavities 7 are pressurized and expanded. Under the restriction of the external shell 6, they can only overflow and expand from the annular notch 8 until they are tightly fitted to the inner wall of the grouting pipe 1 and then the gas injection is stopped. The position of the slurry stop plug 4 is fixed and the upper and lower sides of the slurry discharge hole 2 are closed. Then the external grouting device supplies slurry and flows into the designated position after passing through the slurry supply pipe 3, the slurry supply hole 5, the slurry discharge space and the slurry discharge hole 2, thereby achieving the purpose of designated grouting.

[0042] When it is necessary to grout the next grouting hole 2, the two internal elastic sealing cavities 7 are depressurized, and then the slurry supply pipe 3 is pulled out to the designated position, and the above operation is repeated, thereby achieving the purpose of layered grouting.

[0043] In particular, considering that the internal elastic sealing cavity 7 will inevitably come into contact with the slurry during the expansion and contraction process, and the coarse slurry particles may be attached to the outer wall of the internal elastic sealing cavity 7, when it expands again, there may be some solidified slurry affecting its expansion and sealing effect. At the same time, when it contracts, some solidified slurry may affect its effective contraction and destroy the smoothness of its outer wall. At the same time, there may be rust and the like in the grouting pipe 1, which will also affect the sealing effect between it and the outer wall when the internal elastic sealing cavity 7 expands. Therefore, in this embodiment, an oil sealing system is additionally provided, specifically, an oil supply pipe 11 connected to an external oil supply device is provided in the grouting pipe 1, the bottom end of the oil supply pipe 11 passes through the upper slurry stop plug 4 and is connected to the top of the lower slurry stop plug 4, and an oil outlet hole is respectively opened on the pipe body above the two slurry stop plugs 4, namely a first oil outlet hole 12 and a second oil outlet hole 13, the inner diameter of the first oil outlet hole 12 is larger than the inner diameter of the second oil outlet hole 13, so that the two can The invention relates to a method for synchronously supplying oil, and a specific method for using the same is as follows: when the internal elastic sealing cavity 7 is initially expanded or not expanded, oil is first supplied through the first oil outlet 12 and the second oil outlet 13 through the external oil supply device, and the oil overflows into the external shell 6 or the structure of the internal elastic sealing cavity 7, and then the internal elastic sealing cavity 7 is expanded by air injection, and the overflowed oil can contact with the part of the internal elastic sealing cavity 7 that expands out of the external shell 6 to infiltrate its surface, and the oil supply can be stopped after continuing to supply oil for a period of time after the expansion is completed. In this process, the oil can lubricate the outer wall of the internal elastic sealing cavity 7 to facilitate its effective expansion, and at the same time, it can effectively infiltrate the inner wall of the grouting pipe 1 to avoid damage from rust, and the oil can effectively avoid damage to the internal elastic sealing cavity 7 by solidification slurry, and can effectively fill the gap formed by the solidification slurry adhering to the outer wall of the internal elastic sealing cavity 7 after its expansion, and at the same time, the infiltration of the oil facilitates the removal of the solidification slurry during the expansion and contraction of the internal elastic sealing cavity 7, so that the outer wall can be effectively kept smooth for easy sealing.

[0044] In particular, because the grouting pipe 1 can be used in many ways, for example, in bored piles, after the bored piles are cast to form a pile body, grouting is required on its outer wall to fill the surrounding soil to consolidate it and increase the soil strength. Therefore, the grouting pipe 1 is needed. Even if the above-mentioned grouting pipe 1 is layered grouting, it can only discharge slurry at a single point, which is not conducive to grouting around the pile body. Therefore, in this embodiment, the part of the grouting pipe 1 where each slurry discharge hole 2 is located is also connected to an annular slurry discharge pipe 14 that wraps it up, and overflow holes 15 are evenly opened on the annular slurry discharge pipe 14. Through the above-mentioned arrangement, grouting can be effectively performed around the pile body to achieve the grouting purpose. At the same time, because the annular slurry discharge pipe 14 is connected to the grouting pipe 1 at both ends, a slurry discharge hole 2 can be opened at both ends to speed up the slurry discharge speed.

[0045] In particular, in order to facilitate the fixing of equipment, when grouting the periphery of the bored pile is performed, the grouting pipe 1 and the annular grouting pipe 14 are both fixedly installed in the steel cage of the bored pile.

[0046] In particular, in order to prevent the slurry outside the slurry outlet hole 2 from flowing back into the grouting pipe 1 after the grouting is completed, in the present embodiment, a one-way check device 27 installed in the corresponding annular slurry outlet pipe 14 is provided on the outer wall of the grouting pipe 1 corresponding to each slurry outlet hole 2, so that the slurry can only flow out but not in, and the grouting pipe 1 can be effectively kept free of slurry. Example

[0047] Combination Figure 5 , this embodiment provides a layered grouting device, the equipment structure is similar to that of embodiment 1, and the main difference is that the slurry stopper 4 is improved. In this embodiment, the external shell 6 is specifically composed of a coaxially distributed upper cover 16, a plurality of middle support layers 17 and a lower cover 18, all of which are sleeved on the slurry supply pipe 3 and threadedly connected to its outer wall. The upper cover 16 is specifically composed of a first transverse circular plate 19 and a first annular vertical enclosure 20 that is integral with the first transverse circular plate 19 and arranged at the bottom of its outer edge. The middle support layer 17 is specifically composed of a cylindrical cavity 21 and a second annular vertical enclosure 22 that is arranged at the outer edge of the top end and the outer edge of the bottom end of the cylindrical cavity 21. The lower cover 18 is specifically composed of a second transverse circular plate 23 and a third annular vertical enclosure 24 that is integral with the second transverse circular plate 23 and arranged at the top of its outer edge. The inner and outer diameters of all the annular vertical enclosures are the same. The internal elastic sealing cavity 7 is specifically composed of a plurality of sleeves on the slurry supply pipe 3 and the outer diameter of the first annular vertical enclosure 20 is the same as that of the first annular vertical enclosure 20. The enclosing plate 20 is composed of a cylindrical elastic sealing cavity 25 with the same inner diameter, and a cylindrical elastic sealing cavity 25 is respectively arranged between the upper cover 16 and the adjacent middle supporting layer 17, between two adjacent middle supporting layers 17, and between the lower cover 18 and the adjacent middle supporting layer 17. The distance between the bottom of the upper cover 16 and the top of the adjacent middle supporting layer 17, the distance between the adjacent middle supporting layers 17, and the distance between the top of the lower cover 18 and the bottom of the adjacent middle supporting layer 17 are the same as the thickness of the cylindrical elastic sealing cavity 25. Two adjacent cylindrical elastic sealing cavities 25 in the same slurry stop plug 4 are connected by a high-pressure pipe 26, and two adjacent cylindrical elastic sealing cavities 25 in two slurry stop plugs 4 are connected by a connecting pipe 9, and the cylindrical elastic sealing cavity 25 at the top is connected to the external air supply pipe 10.

[0048] Through the above arrangement, the outer shell 6 is divided into an upper cover 16, multiple middle support layers 17 and a lower cover 18, which simplifies the structure of the equipment on the one hand and facilitates the installation of the equipment on the other hand. A cylindrical elastic sealing cavity 25 is arranged between the upper and lower covers 18 and the middle support layer 17 and between adjacent middle support layers 17, which can effectively limit the position thereof and form a multi-layer sealing effect at the same time. The high-pressure pipe 26 and the connecting pipe 9 can effectively form all the cylindrical elastic sealing cavities 25 into a whole for air supply and pressure relief.

[0049] In particular, in order to facilitate the oil to overflow, in the present embodiment, the first transverse circular plate 19 is replaced by an arc-shaped plate protruding upward, so that the oil can overflow quickly under the action of gravity.

[0050] In particular, in order to prevent the outer edge of the annular enclosure from damaging the cylindrical sealing cavity, in the present embodiment, the exposed edge of each annular enclosure is arc-shaped. Example

[0051] Combination Figure 6 In this embodiment, the equipment structure is the same as that in embodiment 2, and the main difference is that in order to effectively utilize the gap between the expanded exposed parts of adjacent cylindrical elastic sealing cavities 25, in this embodiment, oil is injected to improve the sealing effect. Therefore, it is necessary to expand the cylindrical elastic sealing cavity 25 at the bottom of each grouting plug 4 until it contacts the inner wall of the grouting pipe 1 before oil can be supplied. Therefore, in this embodiment, a pressure valve 28 is also fixedly installed on each high-pressure pipe 26. The pressure valve 28 is bidirectional and can be opened only when the pressure requirement is met. For example, in this embodiment, the pressure valve 28 is specifically a rubber plug with a pressure relief hole in the middle. It is fixedly installed in the high-pressure pipe 26. Under normal pressure, the pressure relief hole is squeezed and closed by itself due to the influence of its own elasticity. When the positive pressure or negative pressure inside it reaches the opening pressure, the pressure relief hole opens, allowing the gas to flow into and out of the corresponding cylindrical elastic sealing cavity 25. At the same time, in this embodiment, the pressure required for the cylindrical elastic sealing cavity 25 to expand to contact the inner wall of the grouting pipe 1 is less than the pressure required for the pressure valve 28 to open. Two branch pipes 30 are provided at the bottom of the external air supply pipe 10, and each branch pipe 30 is respectively connected to the cylindrical elastic sealing cavity 25 at the bottom of a grouting plug 4, and the connecting pipe 9 is cancelled.

[0052] Through the above arrangement, before oil sealing, the cylindrical elastic sealing cavity 25 at the bottom of the two slurry stop plugs 4 is first expanded to contact the inner wall of the grouting pipe 1, and then oil is supplied. After the oil overflows to the top of the first horizontal circular plate 19, the oil supply is stopped, and then air is supplied to the cylindrical elastic sealing cavity 25 again. After the air pressure is greater than the opening pressure of the pressure valve 28, the cylindrical elastic sealing cavity 25 in each slurry stop plug 4 expands from bottom to top in sequence. There is an oil layer between two adjacent cylindrical elastic sealing cavities 25. On the one hand, it can effectively fill the gap between the two and enhance the sealing effect. On the other hand, it can effectively infiltrate the outer wall of the cylindrical sealing cavity to keep it smooth and clean, which can reduce the adhesion effect of the slurry and facilitate its expansion and contraction.

[0053] In particular, in order to avoid the phenomenon that the negative pressure when the cylindrical elastic sealing cavity 25 is contracted causes it to shrink into a ball, a support frame 29 is fixedly installed on the end of each high-pressure pipe 26 in the corresponding cylindrical elastic sealing cavity 25, and the end of the branch pipe 30 can also be connected to the support frame 29, so that when the external pressure supply device generates negative pressure, the support frame 29 can effectively support the cylindrical elastic sealing cavity 25 to avoid shrinking into a ball. When negative pressure is generated, the cylindrical elastic sealing cavity 25 in the same slurry stopper 4 shrinks from bottom to top, and when the air pressure in the cylindrical elastic sealing cavity 25 below is negative and the pressure difference with the cylindrical elastic sealing cavity 25 above it reaches the corresponding pressure of the pressure valve 28 opening pressure and the pressure valve 28 is opened, the cylindrical elastic sealing cavity 25 above it begins to shrink. At this time, the oil also flows downward from bottom to top, which can infiltrate and rinse the outer wall of the cylindrical elastic sealing cavity 25, reducing the degree of slurry adhesion to the outer wall of the cylindrical elastic sealing cavity 25.

[0054] The one-way check device 27 in Examples 1-3 may specifically be a one-way valve, and its connection method may also be that the pulp outlet hole 2 is connected to the annular pulp outlet pipe 14 through it. Example

[0055] In this embodiment, a method for performing layered grouting using a layered grouting device according to embodiment 3 is provided, and the method comprises the following steps:

[0056] Step 1, after a layered grouting device of Example 3 is placed in its entirety into a bored pile hole, conventional bored piles are made to form a pile body;

[0057] Step 2, insert the whole composed of the slurry supply pipe 3 and the two slurry stoppers 4 into the grouting pipe 1 from the top of the grouting pipe 1, stop at the bottom after the lowest slurry outlet hole 2 is in the slurry outlet space, and fix the top of the slurry supply pipe 3, wherein the order of grouting the slurry outlet holes 2 can be set according to needs, and it does not have to be from bottom to top;

[0058] Step 3: The external pressure supply device inputs high-pressure air into the air supply pipe 10, and the high-pressure air enters the lowest cylindrical elastic sealing cavity 25 in each grout stopper 4 through two branch pipes 30. When the corresponding cylindrical elastic sealing cavity 25 expands to contact the inner wall of the grouting pipe 1 and the pressure valve 28 is not opened, the air supply is stopped;

[0059] Step 4, the external oil supply device is turned on to discharge oil to the top of each stop plug 4 through the oil supply pipe 11 via two oil outlet holes. After the oil level overflows the top of each stop plug 4, the oil supply is stopped, and the external pressure supply device is turned on again;

[0060] Step 5: After the pressure in the cylindrical elastic sealing cavity 25 at the bottom of each slurry stopper 4 is greater than the opening pressure of the pressure valve 28 above it, the airflow enters the cylindrical elastic sealing cavity 25 above it and expands it until the pressure in it is greater than the opening pressure of the pressure valve 28 above it, and then the airflow enters the next cylindrical elastic sealing cavity 25, and the cycle is repeated until the pressure in each cylindrical elastic sealing cavity 25 is greater than the grouting pressure of the slurry, and an oil seal layer is formed between two adjacent cylindrical elastic sealing cavities 25 (refer to Figure 6 Middle shaded part), external pressure supply device;

[0061] Step 6: The external grouting device supplies slurry into the slurry supply pipe 3, and the slurry flows into the slurry outlet space through the slurry supply hole 5, flows into the annular slurry outlet pipe 14 through the one-way check device 27, and overflows through the overflow hole 15 for grouting until the grouting amount reaches the target grouting amount;

[0062] Step 7: After the grouting is completed, the external pressure supply device generates negative pressure, and the air in each cylindrical elastic sealing cavity 25 is extracted to shrink it into the corresponding grout stopper 4, and then the whole composed of the grout supply pipe 3 and the two grout stoppers 4 is pulled to the next grout outlet hole 2;

[0063] Step 8: Repeat steps 1-7 until all grouting holes are grouted.

[0064] In particular, each time the stop plug 4 moves to the target position and before it needs to move to the next target position, the oil supplied in the oil supply pipe 11 can be replaced with tap water to flush the equipment. For example, when the stop plug 4 moves to the target position, high-pressure tap water is first supplied to the oil supply pipe 11 to flush the stop plug 4 body and the inner wall of the grouting pipe 1 to flush out the slurry in the equipment, and then other steps such as oil supply are performed; after a grouting hole 2 is completed and the cylindrical elastic sealing cavity 25 shrinks to the normal state and needs to move to the next target position, high-pressure tap water is supplied to the oil supply pipe 11 to flush the stop plug 4 and the inner wall of the grouting pipe 1 to flush out the slurry in the equipment, so that the equipment can always be kept clean, reducing the possibility and amount of slurry adhering to the outer wall of the cylindrical elastic sealing cavity 25.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for layered grouting using a layered grouting device, characterized in that: The layered grouting device comprises a grouting pipe (1), a plurality of grouting holes (2) are provided on the side wall of the grouting pipe (1) from top to bottom, a grouting supply pipe (3) is provided in the grouting pipe (1), the top end of which is connected to an external grouting device and the bottom end of which is closed, two cylindrical grouting plugs (4) are sleeved on the outer wall of the bottom end of the grouting supply pipe (3) from top to bottom and are fixedly connected to the grouting supply pipe (3), and the outer diameter of the grouting plugs (4) is smaller than the inner diameter of the grouting pipe (1), a grouting space is provided between the two grouting plugs (4), and the grouting supply pipe (3) is located in the grouting space. A slurry supply hole (5) is provided on the inner tube body, each of the slurry stop plugs (4) is composed of an outer shell (6) and an inner elastic sealing cavity (7), a plurality of annular notches (8) are evenly provided on the vertical side wall of the outer shell (6) from top to bottom, the outer wall of the inner elastic sealing cavity (7) is in contact with the inner wall of the outer shell (6), the two inner elastic sealing cavities (7) are connected by a connecting pipe (9), and the upper inner elastic sealing cavity (7) is also connected to the external pressure supply device by an air supply pipe (10); The grouting pipe (1) is further provided with an oil supply pipe (11) connected to an external oil supply device, and the bottom end of the oil supply pipe (11) passes through the upper stop plug (4) and is fixedly connected to the top of the lower stop plug (4), a first oil outlet hole (12) is provided on the oil supply pipe (11) above the upper stop plug (4), and a second oil outlet hole (13) is provided on the oil supply pipe (11) between the two stop plugs (4); The outer wall of the grouting pipe (1) where each grout outlet hole (2) is located is also connected to an annular grout outlet pipe (14) that wraps the grout outlet pipe (1), and overflow holes (15) are evenly opened on the annular grout outlet pipe (14); The outer shell (6) is specifically composed of a coaxially distributed upper cover (16), a plurality of middle support layers (17) and a lower cover (18), all of which are sleeved on the slurry supply pipe (3) and threadedly connected to its outer wall. The upper cover (16) is specifically composed of a first transverse circular plate (19) and a first annular vertical enclosure plate (20) which is integral with the first transverse circular plate (19) and arranged at the bottom of its outer edge. The middle support layer (17) is specifically composed of a cylindrical cavity (21) and a second annular vertical enclosure plate (22) which is arranged at the outer edge of the top end and the outer edge of the bottom end of the cylindrical cavity (21). The lower cover (18) is specifically composed of a second transverse circular plate (23) and a third annular vertical enclosure plate (24) which is integral with the second transverse circular plate (23) and arranged at the top of its outer edge. The inner and outer diameters of all the annular vertical enclosure plates are the same. The elastic sealing cavity (7) is specifically composed of a plurality of cylindrical elastic sealing cavities (25) which are sleeved on the slurry supply pipe (3) and have an outer diameter which is the same as the inner diameter of the first annular vertical enclosure (20). A cylindrical elastic sealing cavity (25) is respectively arranged between the upper cover (16) and the adjacent middle support layer (17), between two adjacent middle support layers (17), and between the lower cover (18) and the adjacent middle support layer (17). The distance between the bottom of the upper cover (16) and the top of the adjacent middle support layer (17), the distance between the adjacent middle support layers (17), and the distance between the top of the lower cover (18) and the bottom of the adjacent middle support layer (17) are the same as the thickness of the cylindrical elastic sealing cavity (25). Two adjacent cylindrical elastic sealing cavities (25) in the same slurry stopper (4) are connected by a high-pressure pipe (26); A pressure valve (28) is also fixedly mounted on each high-pressure pipe (26), and the pressure required for the cylindrical elastic sealing cavity (25) to expand to contact the inner wall of the grouting pipe (1) is less than the pressure required for the pressure valve (28) to open. Two branch pipes (30) are provided at the bottom of the external air supply pipe (10), and each branch pipe (30) is respectively connected to the cylindrical elastic sealing cavity (25) at the bottom of a grouting stopper (4); A one-way check device (27) installed in the corresponding annular slurry outlet pipe (14) is provided on the outer wall of the grouting pipe (1) corresponding to each of the slurry outlet holes (2); The method comprises the following steps: Step 1, after placing the layered grouting device as a whole into the bored pile hole, conventional bored pile construction is performed to form a pile body; Step 2, lowering the slurry supply pipe (3) and the two slurry stoppers (4) from the top of the grouting pipe (1) into the grouting pipe (1) until the target slurry outlet hole (2) is in the slurry outlet space, and then stopping the lowering, and fixing the top of the slurry supply pipe (3); Step 3: The external pressure supply device inputs high-pressure air into the air supply pipe (10), and the high-pressure air enters the lowermost cylindrical elastic sealing cavity (25) in each grouting stopper (4) through two branch pipes (30). When the corresponding cylindrical elastic sealing cavity (25) expands to contact the inner wall of the grouting pipe (1) and the pressure valve (28) is not opened, the air supply is stopped; Step 4: The external oil supply device is opened to discharge oil to the top of each stop plug (4) through the oil supply pipe (11) via the first oil outlet hole (12) and the second oil outlet hole (13); the oil supply is stopped after the oil level overflows the top of each stop plug (4), and the external pressure supply device is opened again; Step 5, making the pressure inside each cylindrical elastic sealing cavity (25) greater than the opening pressure of the pressure valve (28) above it, so that each cylindrical elastic sealing cavity (25) expands to fit tightly with the inner wall of the grouting pipe (1), until the pressure inside each cylindrical elastic sealing cavity (25) is greater than the grouting pressure of the slurry, and then closing the external pressure supply device; Step 6: The external grouting device supplies slurry into the slurry supply pipe (3); the slurry flows into the slurry discharge space through the slurry supply hole (5), flows into the annular slurry discharge pipe (14) through the slurry discharge hole (2) and the one-way check device (27), and overflows through the overflow hole (15) for grouting until the grouting amount reaches the target grouting amount; Step 7: After the grouting is completed, the external pressure supply device generates negative pressure to extract the air in each cylindrical elastic sealing cavity (25) so that it shrinks into the corresponding grout stopper (4), and then pulls the whole composed of the grout supply pipe (3) and the two grout stoppers (4) to the next grout outlet hole (2); Step 8: Repeat steps 1-7 until all grouting holes are grouted.

2. The method according to claim 1, characterized in that The first transverse circular plate (19) is replaced with an upwardly convex arc-shaped plate.

3. The method according to claim 1, characterized in that The exposed edge of each annular vertical enclosure is arc-shaped.

4. The method according to claim 1, characterized in that: The grouting pipe (1) and the annular grouting pipe (14) are both fixedly installed in the steel cage.

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