WO2023016034A1

WO2023016034A1 - Pile end bottom grouting apparatus, cast-in-place pile and construction method therefor

Info

Publication number: WO2023016034A1
Application number: PCT/CN2022/094671
Authority: WO
Inventors: 高永光; 高云飞
Original assignee: 高永光; 高云飞
Priority date: 2021-08-09
Filing date: 2022-05-24
Publication date: 2023-02-16
Also published as: CN113737786A; CN218990144U

Abstract

The present application relates to the technical field of foundations, and relates in particular to a pile end bottom grouting apparatus, a cast-in-place pile and a construction method therefor, aimed at solving the defect in the prior art that grouting cavity rupture timing and condition control is difficult. The pile end bottom grouting apparatus comprises a fixing plate; a grout storage bag, fixed on the fixing plate, wherein the grout storage bag forms an accommodating cavity suitable for accommodating grout, or the grout storage bag and the fixing plate define an accommodating cavity suitable for accommodating grout. The grout storage bag has a filled state in which the inside is filled with grout to bear a pile body, and a collapsed state in which the inside is hollow. The grout storage bag is preset with a fixed limit pressure-bearing strength value, and is fixed in volume in the filled state.

Description

Bottom grouting device at pile end, cast-in-place pile and construction method thereof

technical field

The present application relates to the technical field of foundations, in particular to a grouting device at the bottom of a pile tip, a cast-in-place pile and a construction method thereof.

Background technique

At present, in the foundation field, there are mainly two types of grouting after pouring pile ends: open grouting and closed grouting. Among them, closed grouting mostly adopts steel plate capsule grouting, as described in the invention patent with the announcement number CN110896646B and the name "pile bottom grouting device and its use method and pouring pile body and its construction method", including grouting capsule, The grouting pipe and the fixing plate are grouted into the grouting capsule through the grouting pipe after the cast-in-situ pile is poured to form the enlarged head at the bottom of the pile. However, the grouting capsule expands with the increase of pressure, and the relationship between the grouting pressure and the grouting volume and the volume of the expanding head in the closed grouting cavity are difficult to grasp, resulting in very difficult timing and conditions for the grouting capsule to rupture. It is difficult to control, which in turn affects the bearing capacity of cast-in-place piles.

Contents of the invention

Therefore, the technical problem to be solved in this application is to overcome the defects in the prior art that the timing and conditions of grouting cavity rupture are difficult to control, so as to provide a pile end bottom grouting device that can accurately control the timing and conditions of grouting cavity rupture , cast-in-place pile and its construction method.

In order to solve the above technical problems, the application provides a bottom grouting device for pile ends, including:

fixed plate;

a slurry storage bag fixed on the fixing plate, the slurry storage bag forms an accommodating cavity suitable for accommodating slurry or the slurry storage bag and the fixing plate enclose an accommodating cavity suitable for accommodating slurry, The slurry storage bag has a filled state in which the interior is filled with grout to carry the pile body and a collapsed state in which the interior is hollow. The slurry storage bag is preset with a fixed ultimate compressive strength value and has a fixed volume in the filled state.

Optionally, the pulp storage bag is made of chemical synthetic fiber cloth or plastic film.

Optionally, the pulp storage bag is provided with a weak area, and the pressure bearing strength of the weak area is smaller than that of other parts of the pulp storage bag so as to form a pulp outlet area under pressure.

Optionally, also include:

The grouting pipe communicates with the inner cavity of the grout storage bag and is suitable for grouting into the grout storage bag;

The first one-way valve is located at the communication position between the grouting pipe and the grout storage bag, and is suitable for blocking the blockage in the grout storage bag from entering the grouting pipe.

Optionally, a first grout hole is opened on the wall of the grouting pipe, and the first one-way valve includes:

The first water-stop tape is wound around the part where the grouting pipe is provided with the first grouting hole;

The first rubber sleeve is directly or indirectly placed on the outside of the first waterproof tape;

The first water-stop tape and the first rubber sleeve have a sealing state tightened toward the grouting pipe, and an open state forming a gap with the grouting pipe due to the pressure inside the grouting pipe;

The first hard sheet is sandwiched between the first waterproof tape and the first rubber sleeve, and is arranged corresponding to the first slurry outlet.

Optionally, the grouting pipe includes:

The first pulp outlet is located in the cavity of the pulp storage bag;

an interface passing through the fixing plate and communicating with the first pulp outlet;

The slurry feeding pipe is in sealing communication with the interface.

Optionally, the fixing plate is an annular plate, and the pulp storage bag is an annular structure adapted to the annular plate.

Optionally, the edge of the inner ring of the fixing plate is provided with an annular stopper extending to the inner ring of the slurry storage bag.

Optionally, also include:

The grout filling pipe communicates with the inner area of the annular stopper and is suitable for grouting into the pile hole;

The second one-way valve is located at the communication position between the grout replenishing pipe and the inner area of the annular stopper, and is suitable for preventing blockages in the pile hole from entering the grout replenishing pipe.

Optionally, a second slurry outlet hole is opened on the wall of the slurry replenishing pipe, and the second one-way valve includes:

The second water-stop tape is wrapped around the part where the second grout hole is opened in the grout filling pipe;

The second rubber sleeve is directly or indirectly placed on the outside of the second waterproof tape;

Both the second water-stop tape and the second rubber sleeve have a sealed state tightened towards the grout filling pipe, and an open state forming a gap with the grout filling pipe due to the internal pressure of the grout filling pipe;

The second hard sheet is sandwiched between the second waterproof tape and the second rubber sleeve, and is arranged corresponding to the second slurry outlet.

Optionally, the grout replenishing pipe has a second slurry outlet extending to the inner area of the annular baffle, and the second slurry outlet is an annular pipeline extending along the inner wall of the annular baffle.

Optionally, a detection port is provided on the fixing plate, and the detection port is suitable for filling the pulp storage bag with medium.

Optionally, also include:

The protective cover is detachably connected with the fixing plate, and is suitable for covering the outside of the slurry storage bag before construction.

The application also provides a cast-in-place pile, comprising:

The aforementioned pile end bottom grouting device;

The reinforcement cage is connected with the fixed plate of the grouting device at the bottom of the pile end.

The application also provides a construction method for the above-mentioned cast-in-place pile, which comprises the steps in turn:

S1. forming a pile hole, and cleaning the sediment in the pile hole;

S2. Sinking the steel cage with the bottom grouting device at the bottom of the pile installed at the lower end to the bottom of the pile hole;

S3. Pouring concrete into the pile hole to form a cast-in-situ pile;

S4. Injecting grout into the grout storage bag to form a pile bottom expansion head.

Optionally, in step S4, control is performed according to the properties of the soil forming the pile hole: if it is sandy soil, control the actual grouting amount and grouting pressure to be greater than the preset value of the grout storage bag, so that the grout storage Bag rupture; if it is cohesive soil, control the actual grouting volume and grouting pressure to be less than the preset value of the grout storage bag to avoid the grout storage bag rupture.

The technical solution of the present application has the following advantages:

1. The pile end bottom grouting device provided by this application replaces the existing grouting capsule with a grout storage bag, which has a fixed volume in the filled state and will not expand with the increase of internal pressure, and the preset Fixed ultimate compressive strength value. In actual grouting, if it needs to be broken, just control the actual grouting volume and grouting pressure to be greater than the preset value of the grout storage bag; The preset value of the bag is enough. In this way, the timing and conditions of the rupture of the grout bag can be accurately controlled, so that the volume and shape of the enlarged head at the bottom of the pile can be more accurately grasped, the process and effect of grouting can be controlled, and finally the settlement of the pile bottom can be effectively eliminated, and the durability of the cast-in-situ pile can be greatly improved. Ultimate bearing capacity, lower project cost.

2. In the grouting device at the bottom of the pile end provided by this application, a weak area is provided on the slurry storage bag, and the bearing strength of the weak area is lower than that of other parts of the slurry storage bag. During actual grouting, the weak area will be crushed first to form a grout area. In this way, the weak areas can be set at different positions of the slurry storage bag, or the weak areas can be set in different shapes to meet the needs of different construction scenarios.

3. The bottom grouting device at the pile end provided by this application is designed with a specific one-way valve structure for the case where the grout hole is set on the pipe wall, including a water-stop tape, a hard sheet and a rubber sleeve. When the pressure inside the pipe is greater than the ultimate pressure bearing strength of the waterstop tape, the waterstop tape moves away from the pipe wall under the action of the pressure inside the pipe, so that a slurry outlet gap is formed between the waterstop tape and the pipe wall, and the pressure inside the pipe simultaneously Overcome the elastic effect of the rubber sleeve, make it follow the water-stop tape into an open state, and complete the pulping; when the pressure in the pipe is less than or equal to the ultimate pressure bearing strength of the water-stop tape, the pressure in the pipe is not enough to stretch the water-stop tape, and the water-stop Under the action of the elastic force of the rubber sleeve, the adhesive tape is tightly attached to the pipe wall, and the rubber sleeve turns into a sealed state. In this state, the slurry outside the pipe can be prevented from flowing back into the pipe, thus playing the role of a one-way valve. In addition, the hard sheet can prevent the rubber sleeve from being partially sucked into the pipe through the slurry outlet due to negative pressure, causing damage to the sealing performance.

4. For the bottom grouting device at the pile end provided by this application, the fixed plate is set as an annular plate. When the whole device sinks along the pile hole, the mud water and air in the pile hole will pass through the hole and enter the pile bottom grouting device. Above the grouting device, no vortex that damages the hole wall will be formed between the grouting device at the bottom of the pile and the pile hole, thereby effectively avoiding the problem that the vortex that destroys the hole wall will be formed in the pile hole due to the failure of mud water to be discharged during the descent. Avoid the mud flow between the edge of the fixed plate and the pile hole from scouring and disturbing the wall of the pile hole, effectively prevent the hole wall of the pile hole from collapsing, the sediment at the bottom of the hole exceeds the standard, and the pile is broken, and effectively improve the safety of the cast-in-place pile. Construction quality and progress.

5. The cast-in-place pile provided by the present application has the advantages described in any one of the foregoing solutions because it has the pile end bottom grouting device described in any one of the preceding solutions.

6. The construction method provided by this application can determine the actual grouting volume and pressure according to the nature of the soil, combined with the preset capacity and preset limit bearing strength of the grout storage bag, so that the rupture of the grout storage bag can be accurately controlled. Timing and conditions, and then more accurately control the shape and volume of the expanding head to ensure sufficient bearing capacity.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the specific embodiments or prior art. Obviously, the accompanying drawings in the following description The drawings are some implementations of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

Fig. 1 is the schematic diagram of a kind of implementation structure of the pile end bottom grouting device of the present application;

Fig. 2 is the schematic diagram of another kind of implementation structure of the pile end bottom grouting device of the present application;

Fig. 3 is the top view schematic diagram of the grouting device at the bottom of the pile end of the present application;

Fig. 4 is the structural representation of check valve of the present application;

Fig. 5 is the structural representation of the application cast-in-place pile;

Fig. 6 is the schematic diagram that the present application aims to embody the structure of the grouting pipe;

Fig. 7 is a top view of the polygonal pulp storage bag of the present application.

Explanation of reference signs:

1. Fixed plate; 2. Slurry storage bag; 21. Detection port; 3. Grouting pipe; 31. First slurry outlet; 311. First slurry outlet; 32. Interface; 33. Slurry inlet pipe; 4. The first one-way valve; 41. The first water-stop tape; 42. The first rubber sleeve; 43. The first hard piece; , the second slurry outlet; 7, the second one-way valve; 71, the second water-stop tape; 72, the second rubber sleeve; 73, the second hard sheet; 8, the reinforcement cage.

Detailed ways

The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In addition, the technical features involved in the different embodiments of the present application described below may be combined as long as they do not constitute a conflict with each other.

The application provides a bottom grouting device at the pile end, referring to Fig. 1-Fig. 3, including a fixing plate 1 and a grout storage bag 2, the details are as follows:

The fixing plate 1 can be made of metal or high-strength plastic plate or hard silica gel or other commonly used materials whose hardness can meet the requirements of use. The fixed plate 1 can be fabricated by conventional machining or 3D printing. The shape of the fixed plate 1 is not required, and the shape of the fixed plate 1 can be determined according to the cross-sectional shape of the pile hole.

The slurry storage bag 2 is fixed on the fixed plate 1, and the slurry storage bag 2 forms an accommodating cavity suitable for accommodating slurry or the slurry storage bag 2 and the fixed plate 1 enclose an accommodating cavity suitable for accommodating slurry. The pulp storage bag 2 can be a separate whole and then fixed on the fixing plate 1; it can also be an open structure and then be sealed and connected with the fixing plate 1 to form an accommodating cavity. After the slurry storage bag 2 is filled, it can be spherical (as shown in Figure 2) or cuboid (as shown in Figure 1) or polygonal (as shown in Figure 7) or other common shapes. Determine the shape of the pulp storage bag 2 after filling. Pulp storage bag 2 can be symmetrical structure, also can be asymmetrical structure. The pulp storage bag 2 can be integrally formed by means of weaving, weaving or blowing; it can also be formed by sewing, bonding and other methods after cutting. The connection between the pulp storage bag 2 and the fixed plate 1 can be in the following manner: a groove is provided on the edge of the fixed plate 1, a pinhole is provided in the groove, the edge of the pulp storage bag 2 is placed in the groove, and the groove and the The pulp storage bag 2 is bound to the fixing plate 1 by sewing technology for the pinhole; of course, the pulp storage bag 2 and the fixing plate 1 can also be connected by rivets or chemical glue or other common connection methods. The slurry storage bag 2 has a filling state in which the interior is filled with grout to carry the pile body and a collapsed state in which the interior is hollow. The slurry storage bag 2 is preset with a fixed pressure-bearing strength value and has a fixed volume in the filling state. The so-called filling state here refers to the state in which the inside of the slurry storage bag 2 is filled with slurry and the skin is stretched tightly; the folded state refers to the state in which the inside is not filled with slurry or not filled with slurry, and the skin is not fully stretched. "The volume is fixed in the filling state", that is, the grout storage bag does not have elastic expansion and contraction, and the volume is fixed after the internal grout is filled. This is mainly compared with the grouting capsules in the prior art. The existing grouting capsules are full In the state, as the internal slurry pressure increases, it will continue to expand, and the volume of the slurry storage bag 2 in the present application is fixed in the filled state. The "preset and fixed pressure-bearing strength value" means that when the pulp storage bag 2 is made, the pressure-bearing strength value when it is ruptured under pressure has been designed, and this value is a fixed value. The existing grouting capsule, because it becomes larger with the increase of the internal grout pressure, and is easily disturbed by the external pile hole wall after expansion, the bearing strength value when it ruptures is not a fixed value.

The bottom grouting device at the pile end of the present application adopts a grout storage bag 2 with a constant volume under the filling state. The ultimate compressive strength and limit volume of the grout storage bag 2 are determined, and will not be continuously filled like the existing grouting capsules. Therefore, the actual grouting pressure and grouting amount can be determined according to the preset limit volume and limit bearing strength of the grout storage bag 2, so as to accurately control the rupture timing and rupture conditions of the grout storage bag 2.

Preferably, the slurry storage bag 2 can be made of chemical synthetic fiber cloth, such as polyester, nylon, acrylic fiber, etc.; it can also be made of plastic film, such as polyvinyl chloride, polyethylene, polypropylene, etc. Specifically, the strength of the plastic film and the chemical synthetic fiber must be able to meet the requirements of filling the concrete slurry, which is the most basic condition known to those skilled in the art. Of course, in other embodiments, the slurry storage bag 2 can also be made of other common materials, but it must be suitable for accommodating concrete slurry, and the volume is fixed in a filled state. Specifically, the pulp storage bag 2 can be a single layer or a multi-layer structure.

As a further improvement, a weak area is provided on the pulp storage bag 2, and the pressure bearing strength of the weak area is smaller than that of other parts of the pulp storage bag 2 to form a pulp outlet area under pressure. The weak area can be a strip or a circle or any other shape, which is mainly determined by the form of the required slurry.

It has the following effects: the setting of the weak area can more accurately control which specific position of the slurry storage bag 2 is to be injected, and in what form the slurry is injected, which further improves the controllability of the rupture of the slurry storage bag 2 and can meet various requirements. The needs of different construction scenarios.

Of course, in other embodiments, the pulp storage bag 2 may also be uniform, that is, no weak area is provided.

As a further improvement, referring to Figure 1 and Figure 2, the bottom grouting device at the pile end also includes:

The grouting pipe 3 communicates with the inner cavity of the grout storage bag 2 and is suitable for grouting into the grout storage bag 2;

The first one-way valve 4 is located at the communication position between the grouting pipe 3 and the grout storage bag 2 , and is suitable for preventing blockages in the grout storage bag 2 from entering the grouting pipe 3 .

It has the following effects: the setting of the first one-way valve 4 can ensure the normal output of the slurry, and can also prevent blockages such as external sediment and sediment from entering the grouting pipe 3 .

Preferably, referring to Fig. 4, a first grout hole 311 is provided on the pipe wall of the grouting pipe 3, and the first one-way valve 4 includes:

The first water-stop tape 41 is wound around the part of the grouting pipe 3 where the first grouting hole 311 is opened;

The first rubber sleeve 42 is directly placed on the outside of the first waterproof tape 41, and the first rubber sleeve 42 can be made of elastic materials such as rubber or soft silica gel;

Both the first water-stop tape 41 and the first rubber sleeve 42 have a sealed state that is tightened toward the direction of the grouting pipe 3, and an open state where a gap is formed between the grouting pipe 3 and the grouting pipe 3 by the pressure in the grouting pipe 3; in the sealed state The first water-stop tape 41 is tightly attached to the grouting pipe 3 under the tightening effect of the first rubber sleeve 42. In the opened state, a gap is formed between the first water-stop tape 41 and the grouting pipe 3, and the grout inside the grouting pipe 3 can be discharged through said gap;

The first hard sheet 43 is sandwiched between the first waterproof tape 41 and the first rubber sleeve 42, and is set corresponding to the first slurry outlet 311; the first hard sheet 43 is made of metal sheet or hard plastic or other hard Made of high quality material.

It has the following effects: the water-stopping effect of the first water-stopping tape 41 is better, which can improve the sealing performance of the one-way valve; the first rubber sleeve 42 has good elasticity, which can ensure the reset of the first water-stopping tape 41 on the one hand, On the other hand, sufficient tightening force can also be provided to ensure that the first waterproof tape 41 is closely attached to the wall of the grouting pipe 3 in a sealed state; the hardness of the first hard sheet 43 is relatively high, and can resist Negative pressure prevents the flexible first rubber sleeve 42 and the first waterproof tape 41 from being partially sucked into the pipe through the first slurry outlet 311, causing structural damage and damage to the sealing performance.

As an improved structure of the above technical solution, a layer of rubber sleeve can be added between the first waterproof adhesive tape 41 and the first hard sheet 43, that is, the first rubber sleeve 42 is indirectly sleeved on the first stopper through the added rubber sleeve. On the water-stop adhesive tape 41, so compared with the aforementioned structure, the first water-stop adhesive tape 41 is in full contact with the added rubber sleeve, and the rubber sleeve has a better locking effect on the first water-stop adhesive tape 41.

Preferably, referring to Fig. 1-Fig. 3, the grouting pipe 3 includes:

The first slurry outlet 31 is located in the cavity of the slurry storage bag 2; the shape of the first slurry outlet 31 can be determined according to the shape of the slurry storage bag 2, for example, the slurry storage bag 2 is an annular structure, and the first slurry outlet The grout part 31 is correspondingly configured as an annular tubular shape adapted to the grout storage bag 2, so that it can extend to different positions of the grout storage bag 2, so that the grouting is more uniform;

The interface 32 passes through the fixed plate 1 and communicates with the first slurry outlet 31;

The slurry feeding pipe 33 is in sealing communication with the interface 32 .

The connection between the interface 32 and the slurry inlet pipe 33 can be threaded connection, flange connection, welding connection, socket connection or pipeline adhesive connection, etc.

It has the following effects: during grouting, the grout enters from the grout inlet pipe 33, reaches the first grout outlet 31 through the interface 32, and then enters the grout storage bag 2, making grouting more convenient.

Preferably, referring to FIG. 3 , the fixing plate 1 is an annular plate, and the pulp storage bag 2 is an annular structure adapted to the annular plate. The "ring" here is preferably a circular ring, but not limited to a circular ring. The specific shape of the ring is determined according to the shape of the pile hole. For example, if the pile hole is square, a square ring structure is used. The position of the "annular" inner hole is preferably a center position coaxial with the outer edge of the ring, but it is not limited to this position, and can also be arranged eccentrically.

It has the following effects: the ring-shaped fixing plate 1 and the grout storage bag 2 structure make the grouting device at the bottom of the pile tip sink toward the bottom of the pile hole, and the mud water and air in the pile hole will pass through the annular inner hole and enter the pile Above the grouting device at the bottom of the pile end, no vortex that destroys the hole wall will be formed between the grouting device at the bottom of the pile end and the pile hole, thereby effectively avoiding that the mud water cannot be discharged in the pile during the descent of the bottom grouting device at the pile end. The problem of vortex that destroys the hole wall is formed in the pile hole, avoiding the mud flow between the edge of the fixed plate 1 and the pile hole to scour and disturb the hole wall, effectively preventing the hole wall of the pile hole from collapsing, the sediment at the bottom of the hole exceeding the standard, and the pile from breaking problems, effectively improving the construction quality and progress of cast-in-place piles.

As a further improvement, referring to FIG. 1 and FIG. 2 , the inner ring edge of the fixing plate 1 is provided with an annular stopper 5 extending to the inner ring of the slurry storage bag 2 . It can be made of metal or high-strength plastic plate or hard silica gel or other commonly used materials whose hardness can meet the needs of use. The annular stopper 5 can be fixed on the inner ring edge of the fixed plate 1 ; it can also be integrally formed with the fixed plate 1 . When the slurry storage bag 2 is in an open structure, the slurry storage bag 2 can be sealed and connected with the fixing plate 1 and the ring stopper 5 at the same time to form an accommodating cavity. The connection between the pulp storage bag 2 and the annular stopper 5 can be in the following manner: a groove is provided on the edge of the annular stopper 5, and a pinhole is provided in the groove, and the edge of the slurry storage bag 2 is placed in the groove, and the edge of the slurry storage bag 2 is placed in the groove, The grooves and pinholes are used to bind the pulp storage bag 2 to the ring stopper 5 by sewing technology; of course, the pulp storage bag 2 and the ring stopper 5 can also be connected by rivets or chemical glue or other common connection methods.

It has the following effects: in the construction process of cast-in-place piles, it is necessary to pour concrete into the reinforcement cage 8 installed with the bottom grouting device at the pile end to form cast-in-place piles, and the above-mentioned annular stopper 5 can effectively form a gap between the concrete and the cast-in-place pile at the edge of the hole. The barriers separated by the slurry storage bag 2 are used to prevent the concrete from wrapping the slurry storage bag 2 through the inner hole of the fixing plate 1 when pouring concrete towards the reinforcement cage 8, so as to prevent the slurry storage bag 2 from being affected by the concrete wrapping. The problem of post-pile grouting effect.

The grouting pipe 6 communicates with the inner area of the annular stopper 5 and is suitable for grouting into the pile hole;

The second one-way valve 7 is located at the communication position between the grout replenishing pipe 6 and the inner area of the annular stopper 5 , and is suitable for preventing blockages in pile holes from entering the grout replenishing pipe 6 .

It has the following effects: through the grouting pipe 6, the inner area of the ring stopper 5 can be simply and conveniently grouted, eliminating the virtual tip and dry ballast formed by the concrete segregation at the bottom of the pile due to the large drop, and effectively filling the ring stopper 5 The internal area thus enhances the strength of the pile bottom. The setting of the second one-way valve 7 can ensure the normal output of the grout, and can also prevent blockages such as external silt and sediment from entering the grouting pipe 3 .

Preferably, referring to Fig. 4, a second slurry outlet hole 611 is opened on the wall of the slurry replenishing pipe 6, and the second one-way valve 7 includes:

The second water-stop adhesive tape 71 is wound around the part where the grout filling pipe 6 is provided with the second grout hole 611;

The second rubber sleeve 72 is directly placed on the outside of the second waterproof tape 71, and the second rubber sleeve 72 can be made of elastic materials such as rubber or soft silica gel;

Both the second water-stop tape 71 and the second rubber sleeve 72 have a sealed state that is tightened toward the direction of the grout replenishing pipe 6, and an open state where a gap is formed between the grout replenishing pipe 6 and the grout replenishing pipe 6 under the sealed state. The second water-stop tape 71 is tightly attached to the grout filling pipe 6 under the tightening effect of the second rubber sleeve 72. In the opened state, a gap is formed between the second water-stop tape 71 and the grout filling pipe 6, and the grout inside the grout pipe 6 can be discharged through said gap;

The second hard sheet 73 is sandwiched between the second waterproof tape 71 and the second rubber sleeve 72, and is set corresponding to the second slurry outlet 611; the first hard sheet 43 is made of metal sheet or hard plastic or other hard Made of high quality material.

It has the following effects: the second water-stop tape 71 has a better water-stop effect, which can improve the sealing performance of the one-way valve; the second rubber sleeve 72 has better elasticity, which can ensure the reset of the second water-stop tape 71 on the one hand, On the other hand, sufficient tightening force can also be provided to ensure that the second waterproof tape 71 is tightly attached to the wall of the grouting pipe 6 in a sealed state; the hardness of the second hard sheet 73 is relatively high, and can resist The negative pressure prevents the flexible second rubber sleeve 72 and the second water-stop tape 71 from being partially sucked into the pipe through the second slurry outlet 611, causing damage to the structure and sealing performance.

As an improved structure of the above technical solution, a layer of rubber sleeve can be added between the second waterproof adhesive tape 71 and the second hard sheet 73, that is, the second rubber sleeve 72 is indirectly sleeved on the second stopper through the added rubber sleeve. On the water-stop adhesive tape 71, so compared with the aforementioned structure, the second water-stop adhesive tape 71 is in full contact with the added rubber sleeve, and the rubber sleeve has a better locking effect on the second water-stop adhesive tape 71.

Preferably, referring to FIG. 1 and FIG. 2 , the grout feeding pipe 6 has a second slurry outlet 61 extending to the inner area of the annular baffle 5 , and the second slurry outlet 61 is an annular pipeline extending along the inner wall of the annular baffle 5 . Certainly, in other embodiments, the grout feeding pipe 6 may also be a single pipe structure, as shown in FIG. 6 ; or other easily conceivable alternative structures such as two pipes.

It has the following effects: the second slurry outlet 61 is set as an annular pipeline, which can better adapt to the inner area of the annular stopper 5, and transport the slurry to different positions in the area, so that the slurry replenishment is more uniform.

As a further improvement of the above-mentioned technical solution, with reference to Fig. 1 and Fig. 2, a detection port 21 is provided on the fixed plate 1, and the detection port 21 is suitable for filling the medium into the pulp storage bag 2 to verify whether the pulp storage bag 2 leaks and /or the amount of pressure that can be tolerated.

It has the following effects: the setting of the detection port 21 can obtain the limit volume and limit bearing strength of the slurry storage bag 2 through tests, which is convenient for obtaining more accurate preset values, thereby facilitating follow-up construction for the timing and timing of the slurry storage bag 2 rupture. Accurate control of conditions.

As a further improvement of the above technical solution, the bottom grouting device at the pile end also includes:

The protective cover is detachably connected with the fixing plate 1 and is suitable for covering the outside of the slurry storage bag 2 before construction. The protective cover can be made of aluminum foil, hard plastic or hard silica gel, etc., and is mainly used to protect the slurry storage bag 2 before construction, so as to avoid bumping and damaging the slurry storage bag 2; remove.

The present application also provides a cast-in-place pile, referring to FIG. 5 , which includes the aforementioned bottom grouting device at the pile end and a reinforcement cage 8, and the reinforcement cage 8 is connected to the fixing plate 1 of the bottom grouting device at the pile end.

During specific implementation, the grout feeding pipe 33 and the grout replenishing pipe 6 can be fixedly connected with the reinforcement cage 8 to realize fixation.

In detail, the fixing plate 1, the grouting pipe 3, the annular stopper 5 and the grouting pipe 6 in this application can all be made of high-strength plastics. Specifically, injection molding or 3D printing can be used for one-time molding.

The cast-in-place pile of the present application has the effect of any one of the aforementioned pile end bottom grouting devices because it has any one of the aforementioned pile end bottom grouting devices.

S1. form the pile hole, and clean up the sediment in the pile hole;

S2. Sink the reinforcement cage 8 equipped with the bottom grouting device at the bottom end of the pile to the bottom of the pile hole;

S3. Pour concrete into the pile hole to form a cast-in-situ pile;

S4. Inject grout into the grout storage bag 2 to form a pile bottom expansion head.

In step S4, control is performed according to the properties of the soil forming the pile hole. If it is sandy soil, control the actual grouting amount and grouting pressure to be greater than the preset value of the grout storage bag 2 (the preset value includes two: one is the filling state of the grout storage bag 2 designed when making the grout storage bag 2 the lower volume value, and the other is the preset fixed bearing strength value), so that the slurry storage bag 2 is broken, so that the cement slurry in the slurry storage bag 2 overflows, and the sandy soil around the bottom of the pile is infiltrated and consolidated. , and make the enlarged head of the pile end and the surrounding stratum tightly cemented as a whole. If it is cohesive soil, control the actual grouting amount and grouting pressure to be less than the preset value of the grouting bag 2, so as to avoid the rupture of the grouting bag 2; The expansion head should be as large as possible, thereby greatly improving the ultimate bearing capacity of the cast-in-situ pile and reducing settlement; then, the grouting pipe 6 in the grouting device can directly grout the pile bottom stratum, at this time, the formed expansion head can block The upward return of the grout promotes the development of the grout to the depth of the stratum and expands the scope of foundation reinforcement at the bottom of the pile. Certainly, in other embodiments, if it is sandy soil, the slurry storage bag 2 can also be controlled not to rupture; if it is clayey soil, the slurry storage bag 2 can also be controlled to rupture.

It has the following effects: this construction method utilizes the above-mentioned unique pile end bottom grouting device, and can accurately select whether to rupture, as well as the timing and conditions of the rupture according to different soil properties and the preset value of the grout storage bag 2, so as to be able to adapt Improve the bearing capacity of cast-in-place piles.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims

A pile end bottom grouting device, comprising:

fixed plate (1);

It is characterized in that it also includes:

A slurry storage bag (2), fixed on the fixed plate (1), the slurry storage bag (2) forms an accommodating cavity suitable for accommodating slurry or the slurry storage bag (2) and the fixed plate (1) Enclosing an accommodating cavity suitable for accommodating grout, the grout storage bag (2) has a filling state in which the grout is filled inside to carry the pile body and a collapsed state in which the inside is hollow, and the grout storage bag (2) is prefabricated A fixed ultimate compressive strength value is set and the volume is fixed in the filling state.
The pile end bottom grouting device according to claim 1, characterized in that, the grout storage bag (2) is made of chemical synthetic fiber cloth or plastic film.
The pile end bottom grouting device according to claim 1 or 2, characterized in that, the slurry storage bag (2) is provided with a weak area, and the pressure bearing strength of the weak area is smaller than that of the slurry storage bag (2). ) the bearing strength of other parts to form a slurry area when under pressure.
The pile end bottom grouting device according to claim 1, further comprising:

The grouting pipe (3) communicates with the inner cavity of the grout storage bag (2), and is suitable for grouting into the grout storage bag (2);

The first one-way valve (4) is located at the communication position between the grouting pipe (3) and the grout storage bag (2), and is suitable for blocking the blockage in the grout storage bag (2) from entering the Grouting pipe (3).
The pile end bottom grouting device according to claim 4, characterized in that, a first grout hole (311) is opened on the pipe wall of the grouting pipe (3), and the first one-way valve (4 )include:

The first water-stop adhesive tape (41), wound around the position where the grouting pipe (3) is provided with the first grouting hole (311);

The first rubber sleeve (42) is directly or indirectly placed on the outside of the first waterproof tape (41);

The first water-stop tape (41) and the first rubber sleeve (42) have a tight sealing state towards the grouting pipe (3), and are subject to the internal pressure of the grouting pipe (3). Acting in an open state forming a gap with the grouting pipe (3);

The first hard sheet (43) is sandwiched between the first waterproof adhesive tape (41) and the first rubber sleeve (42), and is arranged corresponding to the first pulp outlet hole (311).
The pile end bottom grouting device according to claim 4 or 5, wherein the grouting pipe (3) comprises:

The first pulp outlet (31) is located in the inner cavity of the pulp storage bag (2);

An interface (32), which passes through the fixed plate (1) and communicates with the first slurry outlet (31);

The slurry feeding pipe (33) is in sealing communication with the interface (32).
The pile end bottom grouting device according to claim 1, characterized in that, the fixing plate (1) is an annular plate, and the slurry storage bag (2) is an annular structure adapted to the annular plate.
The pile end bottom grouting device according to claim 7, characterized in that, the inner ring edge of the fixing plate (1) is provided with an annular stopper (5) extending to the inner ring of the slurry storage bag (2) .
The pile end bottom grouting device according to claim 8, further comprising:

The grout filling pipe (6) communicates with the inner area of the annular stopper (5), and is suitable for grouting into the pile hole;

The second one-way valve (7) is located at the communication position between the grout replenishing pipe (6) and the inner area of the annular stopper (5), and is suitable for blocking the blockage in the pile hole from entering the grout replenishment Tube (6).
The pile end bottom grouting device according to claim 9, characterized in that, a second grout hole (611) is opened on the pipe wall of the grout filling pipe (6), and the second one-way valve (7 )include:

The second water-stop adhesive tape (71) is wound around the position where the second grout hole (611) is opened in the grout filling pipe (6);

The second rubber sleeve (72) is directly or indirectly placed on the outside of the second waterproof tape (71);

Both the second water-stop tape (71) and the second rubber sleeve (72) have a sealing state that is tightened toward the direction of the grout replenishing pipe (6), and are affected by the internal pressure of the grout replenishing pipe (6). An open state that forms a gap with the grout filling pipe (6);

The second hard sheet (73) is sandwiched between the second waterproof adhesive tape (71) and the second rubber sleeve (72), and is arranged corresponding to the second slurry outlet hole (611).
The pile end bottom grouting device according to claim 9 or 10, characterized in that, the grout filling pipe (6) has a second grout outlet (61) extending to the inner area of the annular stopper (5) , the second slurry outlet (61) is an annular pipeline extending along the inner wall of the annular stopper (5).
The pile end bottom grouting device according to claim 1, characterized in that, the fixed plate (1) is provided with a detection port (21), and the detection port (21) is suitable for feeding to the slurry storage bag ( 2) filled with medium.
The pile end bottom grouting device according to claim 1, further comprising:

The protective cover is detachably connected with the fixing plate (1), and is suitable for covering the outside of the slurry storage bag (2) before construction.
A cast-in-place pile, characterized in that it comprises:

The pile end bottom grouting device according to any one of claims 1 to 13;

The reinforcement cage (8) is connected with the fixed plate (1) of the grouting device at the bottom of the pile end.
A construction method for cast-in-place piles according to claim 14, characterized in that, comprising the steps in turn:

S1. forming a pile hole, and cleaning the sediment in the pile hole;

S2. sinking the reinforcement cage (8) with the grouting device at the bottom of the pile end installed at the lower end to the bottom of the pile hole;

S3. Pouring concrete into the pile hole to form a cast-in-place pile;

S4. Injecting grout into the grout storage bag (2) to form a pile bottom expansion head.
The construction method according to claim 15, characterized in that, in step S4, control is performed according to the properties of the soil forming the pile hole: if it is sandy soil, control the actual grouting amount and grouting pressure to be greater than the stored grout The preset value of the bag (2), so that the grout storage bag (2) ruptures; if it is clayey soil, control the actual grouting amount and grouting pressure to be less than the preset value of the grout storage bag (2) to avoid storage The slurry bag (2) is broken.