A device for precise positioning and continuous post-grouting of steel pipe piles

Abstract

The present invention belongs to the technical field of post-grouting, and discloses a precise positioning continuous post-grouting device for steel pipe piles, aiming to solve the problem of poor forming quality existing in the existing post-grouting positioning structure. The present invention includes a floating plug and a lower floating plug. The floating plug and the lower floating plug are connected together by a second pipeline and have a spacing. The floating plug and the lower floating plug are both provided with air bags that can be in sealed contact with the grouting perforated pipe after filling with slurry. The floating plug is connected with a first pipeline for injecting slurry, and the lower floating plug is connected with a third pipeline. The slurry can enter the interior of the floating plug and fill the air bag, the interior of the lower floating plug and fill the air bag, and the space between the floating plug and the lower floating plug through the first pipeline, the second pipeline and the third pipeline. The slurry can also enter the grouting perforated pipe below the lower floating plug.

Description

Technical Field

[0001] The invention belongs to the technical field of post-grouting, and particularly relates to a precise positioning continuous post-grouting device for steel pipe piles. Background Art

[0002] Post-grouting refers to injecting high-pressure slurry through a preset grouting pipe (or grouting conduit), and the slurry acts on the surrounding soil through infiltration, splitting, filling, compaction, etc. to achieve effects such as improving bearing capacity and reducing settlement. Post-grouting technology includes pile bottom post-grouting, pile side post-grouting, and combined pile bottom and pile side post-grouting.

[0003] Meanwhile, during the reinforcement process of soft composite foundations, grouting is also carried out through the grouting pipe, and the slurry passes through the grouting pipe and enters the formation for reinforcement.

[0004] Currently, during post-grouting, the slurry is injected from the upper part of the grouting pipe, and the slurry outlet holes on the grouting pipe are distributed throughout the entire grouting pipe. Since the positions of the respective grouting holes are different, the amount of slurry ejected from each slurry outlet hole is not uniform during the grouting process, resulting in poor grouting quality. Therefore, how to improve the grouting uniformity at the positions of the respective grouting holes of the grouting pipe has always troubled the technicians in this field.

[0005] In view of the above problems, some technical research has also appeared in the prior art. For example, the patent with application number 2018216389456 discloses a grouting anchor cable with uniform grouting, including a steel strand, a tray connected to the steel strand, and a grouting section located on one side of the tray and connected to the steel strand through a lock. The steel strand includes multiple steel ropes, a grouting pipe is arranged in the middle of the steel strand, the grouting section is connected to the grouting pipe, the steel rope is spirally distributed on the grouting pipe, and there is a leakage gap between two adjacent steel ropes, the grouting pipe is provided with a plurality of leakage holes, the leakage holes are distributed along the axial direction of the grouting pipe, a baffle is arranged in the grouting pipe along the axial direction of the grouting pipe, the side wall of the baffle is fitted with the inner wall of the grouting pipe, a grouting pipe is connected to the middle of the baffle, the grouting pipe is arranged through the baffle, and the end of the grouting pipe away from the baffle extends out of the grouting pipe through the grouting section. The grouting anchor cable allows the slurry to be quantitatively injected into the surrounding rock at different depths under the action of the baffle and the partition. However, through the action of the partition and the baffle, when the injection of the leakage holes between the baffles is completed, the grouting pipe between the baffles will also be filled with slurry, and when the baffle and the partition move upward together, the slurry in the area will be driven upward together, thereby forming a cavity in this section of the grouting pipe. The result after the injection is completed is: although a sufficient amount of slurry can be ensured to enter the soil outside the grouting pipe through the leakage holes, there is no slurry in the entire grouting pipe. It is necessary to wait until the injection of the leakage holes on each grouting pipe is completed before injecting slurry into the grouting pipe again for grouting (that is, filling the grouting pipe with slurry). The results of this method are: first, the slurry injected into the subsequent grouting pipe has a different solidification time from the previously injected slurry, resulting in poor integrity between the slurry injected into the soil outside the grouting pipe and the subsequent slurry of the grouting pipe, especially the slurry in the leakage hole of the lower section of the grouting pipe due to the earlier injection time; second, the grouting is divided into two times, which increases the entire grouting time and greatly reduces the construction efficiency; third, due to the setting of multiple sealing rings around the baffle and the partition, when the baffle and the partition are lifted up after the injection of the leakage hole around a section of the grouting pipe is completed, a negative pressure area will be formed in the lower section of the partition. The formation of negative pressure will not only hinder the upward movement of the baffle and the partition, but more importantly, the suction effect of the negative pressure will suck the slurry that has been injected into the leakage hole into the grouting pipe, resulting in cracks and voids in the slurry that has been injected into the soil, greatly reducing the grouting quality.

[0006] For another example, the patent with the application number 2016200125637 discloses a precast pile for anti - uplift bearing with positioning and directional grouting, which includes a pile body main body, a pile cap and a pile tip, and also includes a grouting plug, a recyclable steel pipe and a water filtering device. The pile body main body includes a pile body, grouting holes and pile head enlarged holes. The pile body is a hollow tubular structure with grouting holes provided thereon, pile head enlarged holes provided at both ends, and a recyclable steel pipe or a water filtering device provided inside. The pile head enlarged holes are connected to the pile cap, and the lower pile cap is connected to the pile tip. The grouting plug includes a grouting perforated pipe, a grouting solid pipe, a pneumatic or hydraulic plunger, a pneumatic or hydraulic pipe, a pipe end plug, a limiting ring and a pipeline. The top of the grouting perforated pipe is connected to the grouting solid pipe, and the bottom is connected to the pipe end plug. The grouting perforated pipe is provided with a pipeline, two pneumatic or hydraulic plungers and two limiting rings. The grouting perforated pipe and the pneumatic or hydraulic plunger are connected with a limiting ring. The pneumatic or hydraulic plunger is provided with a pneumatic or hydraulic pipe. The two pneumatic or hydraulic plungers are communicated through the pneumatic or hydraulic pipe, and the pneumatic or hydraulic pipe is connected with a pressure device. This structure is similar to the patent structure of 2018216389456. The difference is that this structure directly uses pneumatic or hydraulic plungers to achieve blockage at both the upper and lower ends, so that the slurry can be between the upper and lower plungers, and the slurry is injected into the soil outside the grouting pipe from the slurry leakage holes on the grouting pipe between the two plungers. Similarly, the problems existing in this structure are as described above and will not be elaborated here. Summary of the Invention

[0007] In order to solve the problem of poor forming quality existing in the existing post - grouting positioning structure, the present invention provides a device for precise positioning and continuous post - grouting of steel pipe piles, which can not only ensure the injection volume of each grouting hole on the grouting pipe, but also timely fill the inside of the grouting pipe with slurry, so that the slurry ejected from the grouting holes of the grouting pipe can timely form a whole with the slurry inside the grouting pipe, greatly improving the integrity of post - grouting and the grouting quality.

[0008] In order to solve the technical problems, the technical solution adopted by the present invention is:

[0009] A device for precise positioning and continuous post - grouting of steel pipe piles, which is used for grouting by being sleeved inside a grouting perforated pipe. It is characterized in that it includes a floating plug and a lower floating plug. The floating plug and the lower floating plug are connected together through a second pipeline and have a spacing. Both the floating plug and the lower floating plug are provided with air bags that can be in sealed contact with the grouting perforated pipe after being filled with slurry. The floating plug is connected with a first pipeline for injecting slurry, and the lower floating plug is connected with a third pipeline. The slurry can enter the inside of the floating plug and fill the air bag, the inside of the lower floating plug and fill the air bag, and the space between the floating plug and the lower floating plug through the first pipeline, the second pipeline and the third pipeline. The slurry can also enter the grouting perforated pipe below the lower floating plug.

[0010] In some embodiments, both the floating plug and the lower floating plug include an upper cover plate and a lower cover plate, and there is a spacing between the upper cover plate and the lower cover plate; an airbag is connected between the upper cover plate and the lower cover plate, and through holes are formed in both the upper cover plate and the lower cover plate. The through holes are closer to the outer edges of the upper cover plate and the lower cover plate than the connection positions of the airbag with the upper cover plate and the lower cover plate, and when the airbag is filled with slurry, it can block the through holes, and when the airbag is not filled with slurry, the through holes can be exposed; a sealed cavity is formed between the upper cover plate, the lower cover plate and the airbag. A first pipe is connected to the upper cover plate of the floating plug, passes through the upper cover plate of the floating plug and communicates with the cavity of the floating plug. The first pipe is used to connect with a grouting pipe; the upper end of the second pipe is fixedly connected to the upper cover plate of the floating plug, and the lower end of the second pipe sequentially passes through the lower cover plate of the floating plug and the upper cover plate of the lower floating plug and then is fixedly connected to the lower cover plate of the lower floating plug. A third pipe is connected to the upper cover plate of the lower floating plug, passes through the upper cover plate of the lower floating plug and communicates with the cavity of the lower floating plug. A plurality of through holes are formed in the circumferential wall of the bottom of the second pipe located in the cavities of the floating plug and the lower floating plug.

[0011] In some embodiments, a discharge channel is formed in the lower cover plate of the lower floating plug, a spring is installed at the bottom of the discharge channel, a piston that is hermetically fitted with the discharge channel is installed at the top of the spring, a feed channel is formed at the top of the piston, a through channel that communicates with the feed channel is formed in the piston, and a spray outlet that can communicate or disconnect from the through channel is provided on the lower cover plate of the lower floating plug.

[0012] In some embodiments, the upper side surface of the lower cover plates of the floating plug and the lower floating plug is a spherical surface or a hemispherical surface, and the second channel is connected to the middle of the arc-shaped groove.

[0013] In some embodiments, a counterweight is disposed around the first pipe extending out of the upper cover body of the floating plug.

[0014] In some embodiments, the number of the third pipes is 1, 2, 3 or 4. When the number of the third pipes is 2, 3 or 4, the third pipes are evenly distributed on the upper cover body of the lower floating plug.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] During the use of the precise positioning continuous post-grouting device for steel pipe piles of the present invention, first, the floating plug and the lower floating plug are placed at appropriate positions on the grouting perforated pipe, such that the grouting holes of the grouting perforated pipe that need to be grouted are located between the floating plug and the lower floating plug. Then, slurry is injected into the first pipe. The slurry enters the cavity of the floating plug along the first pipe, then enters the second pipe through the through holes on the second pipe and enters the cavity of the lower floating plug. The slurry in the cavity of the lower floating plug first passes through the discharge channel, the feed channel of the piston, and the through channel of the piston, and then is ejected through the ejection port of the lower floating plug to fill the grouting perforated pipe below the lower floating plug (at this time, the through channel of the piston is in communication with the ejection port of the lower floating plug), thereby filling the grouting perforated pipe below the lower floating plug and preventing the occurrence of hollowing in the grouting perforated pipe below the lower floating plug. After the grouting perforated pipe below the lower floating plug is filled, as the pressure of the slurry becomes higher and higher, the piston in the lower cover of the lower floating plug gradually slides down under the action of the slurry pressure, so that the through channel and the ejection port are disconnected from each other, and then the grouting fills the airbag of the lower floating plug, so that the airbag expands and is in close contact with the inner wall of the grouting perforated pipe, and at the same time, the whole device is stabilized in the grouting perforated pipe under the action of the counterweight. As more and more slurry is injected, the slurry flows out of the third pipe and fills the space between the floating plug and the lower floating plug, and then is injected into the formation through the grouting holes on the grouting perforated pipe. When the grouting of this section of the grouting perforated pipe is completed, the grouting is stopped, and the whole device (i.e., the floating plug and the lower floating plug) is slowly lifted upward. Along with the decrease in the slurry pressure in the floating plug and the lower floating plug, the piston in the lower cover of the lower floating plug moves upward, so that the through channel on the piston is in communication with the ejection port of the lower cover again, thereby filling the space below the lower floating plug with slurry. That is, when the floating plug and the lower floating plug are lifted upward, the slurry will automatically fill the space vacated by the movement of the floating plug and the lower floating plug. In this way, the grouting of the whole grouting perforated pipe is completed in a cycle. During the use of the present invention, the piston in the lower cover of the lower floating plug can be automatically adjusted according to the change of the slurry pressure, so that the ejection port and the through channel in the lower cover of the lower floating plug are cut off or connected. When the floating plug and the lower floating plug move upward together, the slurry can be automatically filled below the lower floating plug. On the one hand, the slurry is used to fill the inside of the grouting pipe below the lower floating plug, so that the slurry ejected from the grouting holes of the grouting pipe can be integrated with the slurry inside the grouting pipe in time, greatly improving the integrity of the post-grouting and the grouting quality. On the other hand, it avoids the formation of negative pressure at the lower end of the lower floating plug when the floating plug and the lower floating plug are lifted, and avoids the problem of grouting cracks caused by the backflow of the slurry ejected through the grouting holes under the action of the negative pressure, further improving the forming quality.

[0017] In the process of using the present invention, the slurry first fills the grouting flower pipe below the lower floating plug through the first pipe, the second pipe and the third pipe, then fills the airbag of the lower floating plug, and finally fills the airbag of the upper floating plug, so that the air between the upper floating plug and the lower floating plug can be discharged through the through hole, avoiding the situation of holes in the slurry due to the retention of air, and improving the quality of grouting molding. As for the prior art described in the background art of the present application, due to the sealing effect of the grouting plug, the internal gas cannot be completely discharged, resulting in the problem of voids in the solidified slurry. The present invention can avoid the situation of voids caused by the retention (incomplete discharge) of air, and further improve the quality of post-grouting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention during post-grouting of the grouting flower pipe or steel pipe;

[0019] Figure 2 is Figure 1 a partial enlarged schematic view of part A in [FIGURE REFERENCE], in which the through channel on the piston is disconnected from the spray outlet on the lower cover body;

[0020] Figure 3 is a schematic diagram of the state when the through channel on the piston of the present invention is in communication with the spray outlet on the lower cover body;

[0021] Figure 4 is a schematic diagram of the connection state of the airbag of the present invention with the upper cover body and the lower cover body. In this schematic diagram, the airbag is in an unexpanded state, thus exposing the through hole;

[0022] Reference numerals in the figure: 01, rock and soil body; 02, grouting flower pipe (or steel pipe); 03, grouting hole; 04, grouting pipe; 1, upper floating plug; 11, upper cover body; 111, through hole; 112, mounting block; 12, airbag; 13, lower cover body; 131, discharge channel; 132, piston; 133, feed channel; 134, through channel; 135, spray outlet; 136, spring; 2, lower floating plug; 3, first pipe; 4, second pipe; 41, through hole; 5, third pipe; 6, counterweight. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be further described below in conjunction with embodiments. The described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0024] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. The terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In addition, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0025] Combined with the attached Figure 1 to the attached Figure 4 The present invention provides a precise positioning continuous post-grouting device for steel pipe piles, which is used to be sleeved in a grouting perforated pipe 02 for grouting and to precisely grout the grouting holes 03 at various positions in the grouting perforated pipe 02. It includes a floating plug 1 and a lower floating plug 2. The floating plug 1 and the lower floating plug 2 are connected together by a second pipe 4 and have a spacing. Both the floating plug 1 and the lower floating plug 2 are provided with air bags 12 that can be in sealed contact with the grouting perforated pipe 02 after filling with grout. The floating plug 1 is connected with a first pipe 3 for injecting grout. Among them, the first pipe 3 is used to connect with a grouting pipe 04, and grout is injected into the first pipe 3 through the grouting pipe 04. The lower floating plug 2 is connected with a third pipe 5. The grout can enter the interior of the floating plug 1 through the first pipe 3, the second pipe 4, and the third pipe 5 to fill the air bag 12, enter the interior of the lower floating plug 3 to fill the air bag 12, and enter the space between the floating plug 1 and the lower floating plug 2. And the grout can also enter the grouting perforated pipe below the lower floating plug. That is to say, after the grout enters through the first pipe 3, it can fill the air bag of the floating plug 1, the air bag of the lower floating plug 2, and enter the spacing between the floating plug 1 and the lower floating plug 2. Thus, the grouting perforated pipe 02 located between the floating plug and the lower floating plug is filled, and the grout is sprayed into the rock and soil mass 01 through the grouting holes 03 on the grouting perforated pipe 02, so as to impact and extrude the rock and soil mass 01, etc. After the grout solidifies, the rock and soil mass 01 and the grouting perforated pipe 02 form an integral body through the concrete, thus completing the post-grouting reinforcement operation.

[0026] In some embodiments, the upper floating plug 1 and the lower floating plug 2 both include an upper cover plate 11 and a lower cover plate 13, and there is a spacing between the upper cover plate 11 and the lower cover plate 13; an airbag 12 is connected between the upper cover plate 11 and the lower cover plate 13, and through holes 111 are formed in both the upper cover plate 11 and the lower cover plate 13. The through holes 111 are closer to the outer edges of the upper cover plate 11 and the lower cover plate 13 than the connection positions of the airbag 12 with the upper cover plate 11 and the lower cover plate 13, and when the airbag 12 is filled with slurry, it can block the through holes 111, and when the airbag 12 is not filled with slurry, it can expose the through holes 111; a sealed cavity is formed between the upper cover plate 11, the lower cover plate 13 and the airbag 12. A first pipe 3 is connected to the upper cover plate 11 of the upper floating plug 1, passes through the upper cover plate 11 of the upper floating plug 1 and communicates with the cavity of the upper floating plug 1. The first pipe 3 is used to connect with a grouting pipe 04; the upper end of a second pipe 4 is fixedly connected to the upper cover plate 11 of the upper floating plug 1, and the lower end of the second pipe 4 sequentially passes through the lower cover plate 13 of the lower floating plug 2, the upper cover plate 11 of the lower floating plug 2 and then is fixedly connected to the lower cover plate 13 of the lower floating plug 2. A third pipe 5 is connected to the upper cover plate 11 of the lower floating plug 2, passes through the upper cover plate 11 of the lower floating plug 2 and communicates with the cavity of the lower floating plug 2. A plurality of through holes 41 are formed in the circumferential wall at the bottom of the second pipe 5 located in the cavities of the upper floating plug 1 and the lower floating plug 2.

[0027] Combined with the attached Figure 4 , grooves are formed at the lower end of the upper cover plate 11 and the upper end of the lower cover plate 13. Installation blocks 112 are arranged in the grooves. The upper and lower edges of the airbag 12 are respectively clamped in the grooves and fixed by the installation blocks. Then the installation blocks 112 are fixedly connected to the upper cover plate or the lower cover plate 13 through fastening bolts, so as to respectively install the upper and lower edges of the airbag 12 on the upper cover plate and the lower cover plate.

[0028] Since the airbag needs to be in close contact with the circumferential wall of the grouting pipe 02, preferably, the groove is an annular groove and the installation block 112 is annular. In the process of using the airbag structure of the present invention, when the slurry pressure reaches a certain level, the slurry fills the cavities in the upper floating plug and the lower floating plug, thereby driving the airbag to expand and be in close contact and seal with the inner wall of the grouting pipe 02, sealing the slurry in the space between the upper floating plug and the lower floating plug, so as to grout the grouting holes 03 of the grouting pipe 02 and reinforce the rock and soil mass 01.

[0029] When the pouring of the grouting pipe 02 in a certain area (length) is completed, the injection of slurry into the grouting pipe 04 is stopped. Along with the decrease of the slurry pressure, the airbag 12 gradually disengages from the inner wall of the grouting pipe 02, thus facilitating the lifting of the entire device to move along the inside of the grouting pipe.

[0030] Preferably, a lifting lug is provided on the upper cover body 11 of the floating plug 1, and the lifting lug is used for tying a towing rope, and the whole device is driven to move up and down in the grouting perforated pipe 02 through the towing rope.

[0031] Combined with the attached Figure 2 and the attached Figure 3 In some embodiments, a discharge channel 131 is formed in the lower cover plate 13 of the floating plug 2. A spring 136 is installed at the bottom of the discharge channel 131. A piston 132 that is hermetically fitted with the discharge channel 131 is installed at the top of the spring 136. A feed channel 133 is formed at the top of the piston 132. A through channel 134 that communicates with the feed channel 133 is formed in the piston 132. A spray outlet 135 that can communicate or disconnect from the through channel 134 is provided on the lower cover plate 13 of the floating plug 2. Among them, when the slurry pressure is small, the through channel 134 on the piston 132 communicates with the spray outlet 135 on the lower cover body, and when the slurry pressure is large, the through channel 134 on the piston 132 disconnects from the spray outlet 135 on the lower cover body.

[0032] In some embodiments, the upper side surface of the lower cover plate 13 of the floating plug 1 and the floating plug 2 is a spherical surface or a hemispherical surface, and the second channel 4 is connected to the middle of the arc-shaped groove.

[0033] In some embodiments, a counterweight 6 is provided around the first pipe extending out of the upper cover body 11 of the floating plug 1. The counterweight is used to maintain the stability of the whole device, and together with a filled airbag, it prevents the whole device from floating under the action of high-pressure slurry.

[0034] In some embodiments, the number of the third pipes 5 is 1, 2, 3 or 4. When the number of the third pipes is 2, 3 or 4, the third pipes 5 are evenly distributed on the upper cover body of the floating plug. Since the grouting holes 03 on the grouting perforated pipe 02 are evenly distributed, in order to make the grouting of the grouting holes 03 at the same height position of the grouting perforated pipe 02 more uniform, the number of the third pipes is the same as the number of the grouting holes 03 at the same height position on the grouting perforated pipe 02, so as to make the grouting of the grouting holes 03 at the same height position on the grouting perforated pipe 02 more uniform.

[0035] During the use of the precise positioning continuous post - grouting device of the present invention, first, the floating plug and the lower floating plug are placed at appropriate positions on the grouting perforated pipe, so that the grouting holes of the grouting perforated pipe that need to be grouted are located between the floating plug and the lower floating plug. Then, slurry is injected into the first pipe. The slurry enters the cavity of the floating plug along the first pipe, then enters the second pipe through the through - holes on the second pipe and enters the cavity of the lower floating plug. The slurry in the cavity of the lower floating plug first passes through the discharge channel, the feed channel of the piston, and the through - channel of the piston, and then is ejected through the ejection port of the lower floating plug to fill the grouting perforated pipe below the lower floating plug (at this time, the through - channel of the piston is connected to the ejection port of the lower floating plug), so as to fill the grouting perforated pipe below the lower floating plug and prevent the occurrence of hollowing in the grouting perforated pipe below the lower floating plug. After the grouting perforated pipe below the lower floating plug is filled, as the pressure of the slurry becomes higher and higher, the piston in the lower cover of the lower floating plug gradually slides down under the action of the slurry pressure, so that the through - channel and the ejection port are disconnected from each other. Then, the grouting fills the airbag of the lower floating plug, so that the airbag expands and is in close contact with the inner wall of the grouting perforated pipe, and at the same time, the whole device is stabilized in the grouting perforated pipe under the action of the counterweight. As more and more slurry is injected, the slurry flows out from the third pipe and fills the space between the floating plug and the lower floating plug, and then is injected into the formation through the grouting holes on the grouting perforated pipe. When the grouting of this section of the grouting perforated pipe is completed, the grouting is stopped, and the whole device (i.e., the floating plug and the lower floating plug) is slowly lifted upward. Along with the decrease in the slurry pressure in the floating plug and the lower floating plug, the piston in the lower cover of the lower floating plug moves upward, so that the through - channel on the piston is connected to the ejection port of the lower cover again, thereby filling the space below the lower floating plug with slurry. That is, when the floating plug and the lower floating plug are lifted upward, the slurry will automatically fill the space vacated by the movement of the floating plug and the lower floating plug. In this way, the grouting of the whole grouting perforated pipe is completed in a cycle. During the use of the present invention, the piston in the lower cover of the lower floating plug can be automatically adjusted according to the change of the slurry pressure, so that the ejection port and the through - channel in the lower cover of the lower floating plug are cut off or connected. When the floating plug and the lower floating plug move upward together, the space below the lower floating plug can be automatically filled with slurry. On the one hand, the inside of the grouting pipe below the lower floating plug is filled with slurry, so that the slurry ejected from the grouting holes of the grouting pipe can be timely integrated with the slurry inside the grouting pipe, greatly improving the integrity of the post - grouting and the grouting quality. On the other hand, it avoids the formation of negative pressure at the lower end of the lower floating plug when the floating plug and the lower floating plug are lifted, and avoids the problem of grouting cracks caused by the backflow of the slurry ejected through the grouting holes under the action of negative pressure, further improving the forming quality.

[0036] In addition, during the use of the present invention, the slurry first fills the grouting perforated pipe below the lower floating plug through the first pipe, the second pipe and the third pipe, then fills the airbag of the lower floating plug, and finally fills the airbag of the upper floating plug, so that the air between the upper floating plug and the lower floating plug can be discharged through the through hole, avoiding the situation of holes in the slurry due to the retention of air, and improving the quality of grouting molding. As for the prior art described in the background art of this application, due to the sealing effect of the grouting plug, the internal gas cannot be completely discharged, resulting in the problem of holes in the solidified slurry. The present invention can avoid the situation of holes caused by the retention (incomplete discharge) of air, further improve the quality of post-grouting, and improve the accuracy of grouting.

Claims

1. A precise positioning continuous post - grouting device for steel pipe piles, which is used for grouting by being sleeved inside a grouting perforated pipe. It is characterized in that it includes a floating plug and a lower floating plug. The floating plug and the lower floating plug are connected together by a second pipe and have a spacing. Both the floating plug and the lower floating plug are provided with air bags that can be in sealed contact with the grouting perforated pipe after filling with grouting slurry. The floating plug is connected with a first pipe for injecting grouting slurry, and the lower floating plug is connected with a third pipe. The grouting slurry can enter the inside of the floating plug to fill the air bag, the inside of the lower floating plug to fill the air bag, and the space between the floating plug and the lower floating plug through the first pipe, the second pipe and the third pipe. The grouting slurry can also enter the grouting perforated pipe below the lower floating plug. Both the floating plug and the lower floating plug include an upper cover plate and a lower cover plate, and there is a spacing between the upper cover plate and the lower cover plate; an air bag is connected between the upper cover plate and the lower cover plate. Through holes are opened on both the upper cover plate and the lower cover plate. The through holes are closer to the outer edges of the upper cover plate and the lower cover plate than the connection positions of the air bag with the upper cover plate and the lower cover plate. And when the air bag is filled with grouting slurry, it can block the through holes, and when the air bag is not filled with grouting slurry, it can expose the through holes; a sealed cavity is formed between the upper cover plate, the lower cover plate and the air bag. The upper cover plate of the floating plug is connected with a first pipe that passes through the upper cover plate of the floating plug and is communicated with the cavity of the floating plug. The first pipe is used for connecting with a grouting pipe; the upper end of the second pipe is fixedly connected to the upper cover plate of the floating plug, and the lower end of the second pipe sequentially passes through the lower cover plate of the floating plug, the upper cover plate of the lower floating plug and then is fixedly connected to the lower cover plate of the lower floating plug. The upper cover plate of the lower floating plug is connected with a third pipe that passes through the upper cover plate of the lower floating plug and is communicated with the cavity of the lower floating plug. A number of through holes are opened on the circumferential wall of the bottom of the second pipe located in the cavities of the floating plug and the lower floating plug. An outlet channel is opened on the lower cover plate of the lower floating plug. A spring is installed at the bottom of the outlet channel, and a piston that is in sealed cooperation with the outlet channel is installed at the top of the spring. A feed channel is opened at the top of the piston, and a through - channel that is communicated with the feed channel is opened inside the piston. A spray outlet that can be communicated or disconnected with the through - channel is arranged on the lower cover plate of the lower floating plug.

2. The precise positioning continuous post - grouting device for steel pipe piles according to claim 1, It is characterized in that the upper side surface of the lower cover plates of the floating plug and the lower floating plug is a spherical or hemispherical spherical surface, and the second pipe is connected to the middle of the arc - shaped groove.

3. The precise positioning continuous post - grouting device for steel pipe piles according to claim 1 or 2, It is characterized in that a counterweight is arranged around the first pipe extending out of the upper cover plate of the floating plug.

4. The precise positioning continuous post - grouting device for steel pipe piles according to claim 3, It is characterized in that the number of the third pipes is 1, 2, 3 or 4. When the number of the third pipes is 2, 3 or 4, the third pipes are evenly distributed on the upper cover plate of the lower floating plug.

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