A structure and method for improving the bearing capacity of bored piles by drilling holes in piles

Abstract

The present invention discloses a structure and method for improving the bearing capacity of a bored pile by drilling holes in a pile. The structure includes three reinforcement holes vertically drilled from the top of the bored pile to the bottom of the pile. A grouting pipe is installed at the top of the reinforcement hole. A high-pressure pipe valve is installed on the grouting pipe. A cavity area is formed at the bottom of the bored pile in the foundation through high-pressure water flushing. Cement slurry injected into the grouting pipe by a grouting hose forms a connecting column. The cement slurry flows into the cavity area through the reinforcement hole and forms an enlarged head connected to the connecting column. The method includes the following steps: 1. Obtaining a reinforcement hole; 2. Installing a grouting pipe and a high-pressure pipe valve; 3. High-pressure hole cleaning; 4. High-pressure grouting; 5. Forming an enlarged head. The present invention uses high-pressure water to flush and connect the bottom ends of two reinforcement holes, forming a cavity area at the bottom of the bored pile in the foundation, completing cleaning and grouting. The cavity area after grouting forms an enlarged head connected to the connecting column, thereby improving the bearing capacity of the bored pile.

Description

Technical Field

[0001] The invention belongs to the technical field of improving the bearing capacity of bored piles, and in particular relates to a structure and a method for improving the bearing capacity of bored piles by drilling holes in the piles. Background Art

[0002] Bored piles are widely used in various pile foundation projects because of their fast construction speed, small footprint, strong adaptability to various soil layers, and high bearing capacity. Due to the influence of many factors such as geological conditions and construction management, the bearing capacity of the test piles after the construction of bored piles is insufficient, or the deformation requirements cannot be met, or the bearing layer at the pile end is not in an ideal state. It is necessary to improve the bearing capacity of the pile body, reduce the deformation, and strengthen the bearing layer at the pile end. The commonly used methods to deal with the insufficient bearing capacity of bored piles are: after thorough cleaning, a new pile is re-cast in situ to achieve a more thorough treatment. This method has good effect, high difficulty, long cycle, and high cost. It can be selected according to the importance of the project, geological conditions, number of defects and other factors; or two piles are added on both sides of the pile, and the piles are connected with a cap on the top of the pile. This solution will change the pile foundation structure; the existing method has slow daily progress, high labor consumption, and the quality, construction period and economy of the piles cannot be controlled. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a structure for improving the bearing capacity of the bored cast-in-place pile by drilling holes in the pile in view of the deficiencies in the above-mentioned prior art. The structure is novel and reasonable in design. Only three reinforcement holes are vertically drilled from the top to the bottom of the bored cast-in-place pile. The bottom ends of the two reinforcement holes are flushed and connected by high-pressure water to form a cavity area at the bottom of the bored cast-in-place pile in the foundation, and cleaning and grouting are completed with good circulation. An enlarged head is formed in the cavity area after grouting, and the cavity area is integrally connected with the connecting column, thereby effectively improving the bearing capacity of the bored cast-in-place pile. The disturbance to the entire bored cast-in-place pile is small, the construction period is short, the cost is low, a large amount of labor consumption is avoided, the safety is good, and it is easy to promote and use.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a structure for improving the bearing capacity of the bored pile by drilling holes in the pile, characterized in that: it includes a first reinforcement hole, a second reinforcement hole and a third reinforcement hole vertically drilled from the top of the bored pile to the bottom of the pile, the top of the first reinforcement hole is equipped with a first grouting pipe extending into the first reinforcement hole, a first high-pressure pipe valve is installed on the pipe section of the first grouting pipe extending out of the first reinforcement hole, a second grouting pipe extending into the second reinforcement hole is installed on the top of the second reinforcement hole, a second high-pressure pipe valve is installed on the pipe section of the second grouting pipe extending out of the second reinforcement hole, a third grouting pipe extending into the third reinforcement hole is installed on the top of the third reinforcement hole, and the third A third high-pressure pipe valve is installed on the pipe section of the grouting pipe extending out of the third reinforcement hole. The gap between the first grouting pipe and the first reinforcement hole, the gap between the second grouting pipe and the second reinforcement hole, and the gap between the third grouting pipe and the third reinforcement hole are all sealed by the sealing layer. A high-pressure water pump and a high-pressure grouting pump are arranged on the ground beside the bored pile. The water injection pipe cooperates with the grouting pipe through the high-pressure water pump, and the grouting hose cooperates with the grouting pipe through the high-pressure grouting pump. A cavity area is formed at the bottom of the bored pile in the foundation through high-pressure water scouring. Cement slurry injected into the grouting pipe by the grouting hose forms a connecting column. The cement slurry flows into the cavity area through the reinforcement hole and forms an enlarged head integrally connected to the connecting column.

[0005] The structure for increasing the bearing capacity of bored piles by drilling holes in the piles is characterized in that the length of the first grouting pipe, the length of the second grouting pipe and the length of the third grouting pipe are all 50 cm to 100 cm.

[0006] The above-mentioned structure of drilling holes in a pile to improve the bearing capacity of the bored pile is characterized in that the first reinforcement hole, the second reinforcement hole and the third reinforcement hole are evenly arranged in the bored pile around the central axis of the bored pile.

[0007] The structure of drilling holes in piles to improve the bearing capacity of bored piles is characterized in that the diameters of the first reinforcement holes, the second reinforcement holes and the third reinforcement holes are all 8 cm to 10 cm.

[0008] The above-mentioned structure for drilling holes in piles to improve the bearing capacity of bored piles is characterized in that the cement slurry is ultrafine cement slurry, the particle size of the ultrafine cement in the ultrafine cement slurry is 0.2μm~20μm, and the average particle size of the ultrafine cement in the ultrafine cement slurry is 5μm~6μm.

[0009] At the same time, the present invention also discloses a method for improving the bearing capacity of bored piles by drilling holes in piles, which has simple steps and reasonable design. The method is characterized in that the method comprises the following steps:

[0010] Step 1: Obtain reinforcement holes: a first reinforcement hole, a second reinforcement hole and a third reinforcement hole vertically drilled from the top of the bored pile to the bottom of the pile;

[0011] The diameters of the first reinforcement hole, the second reinforcement hole, and the third reinforcement hole are all 8 cm to 10 cm;

[0012] The first reinforcement hole, the second reinforcement hole and the third reinforcement hole are evenly arranged in the bored pile around the central axis of the bored pile;

[0013] Step 2, installing the grouting pipe and the high-pressure pipe valve: installing the first grouting pipe extending into the first reinforcement hole at the top end of the first reinforcement hole, installing the first high-pressure pipe valve on the pipe section of the first grouting pipe extending out of the first reinforcement hole, installing the second grouting pipe extending into the second reinforcement hole at the top end of the second reinforcement hole, installing the second high-pressure pipe valve on the pipe section of the second grouting pipe extending out of the second reinforcement hole, installing the third grouting pipe extending into the third reinforcement hole at the top end of the third reinforcement hole, installing the third high-pressure pipe valve on the pipe section of the third grouting pipe extending out of the third reinforcement hole, and the gap between the first grouting pipe and the first reinforcement hole, the gap between the second grouting pipe and the second reinforcement hole, and the gap between the third grouting pipe and the third reinforcement hole are all sealed by the sealing layer;

[0014] The length of the first grouting pipe, the length of the second grouting pipe and the length of the third grouting pipe are all 50 cm to 100 cm;

[0015] Step 3: High-pressure hole cleaning. The process is as follows:

[0016] Step 301, close the third high-pressure pipe valve, open the first high-pressure pipe valve and the second high-pressure pipe valve, install the water injection pipe on the first grouting pipe, and inject high-pressure water into the first grouting pipe with a high-pressure water pump. The high-pressure water seeps in the foundation at the bottom of the bored pile until it flows into the second grouting pipe, flushes the position at the bottom of the bored pile in the foundation, forms a cavity area, and the high-pressure water overflows from the second grouting pipe with the debris at the bottom of the bored pile until the second grouting pipe overflows with clear water, removes the water injection pipe on the first grouting pipe and installs it on the second grouting pipe, and injects high-pressure water into the second grouting pipe. The high-pressure water seeps in the foundation at the bottom of the bored pile and flows into the second grouting pipe, continues to flush the position at the bottom of the bored pile in the foundation, expands the cavity area, and the high-pressure water overflows from the first grouting pipe with the debris at the bottom of the bored pile until the first grouting pipe overflows with clear water, and then shuts down the high-pressure water pump;

[0017] Step 302, close the first high-pressure pipe valve, open the third high-pressure pipe valve and the second high-pressure pipe valve, install the water injection pipe on the second grouting pipe, and the high-pressure water pump injects high-pressure water into the second grouting pipe. The high-pressure water seeps in the foundation at the bottom of the bored pile until it flows into the third grouting pipe, flushes the position at the bottom of the bored pile in the foundation, expands the cavity area, and the high-pressure water overflows from the third grouting pipe with the debris at the bottom of the bored pile until the third grouting pipe overflows with clear water, removes the water injection pipe on the second grouting pipe and installs it on the third grouting pipe, and the high-pressure water pump injects high-pressure water into the third grouting pipe, and the high-pressure water seeps in the foundation at the bottom of the bored pile and flows into the second grouting pipe, and continues to flush the position at the bottom of the bored pile in the foundation, expands the cavity area, and the high-pressure water overflows from the second grouting pipe with the debris at the bottom of the bored pile until the second grouting pipe overflows with clear water, and then the high-pressure water pump is turned off;

[0018] Step 303, close the second high-pressure pipe valve, open the first high-pressure pipe valve and the third high-pressure pipe valve, install the water injection pipe on the third grouting pipe, and the high-pressure water pump injects high-pressure water into the third grouting pipe. The high-pressure water seeps in the foundation at the bottom of the bored pile until it flows into the first grouting pipe, flushes the position at the bottom of the bored pile in the foundation, expands the cavity area, and the high-pressure water overflows from the first grouting pipe with the debris at the bottom of the bored pile until the first grouting pipe overflows with clear water, removes the water injection pipe on the third grouting pipe and installs it on the first grouting pipe, and the high-pressure water pump injects high-pressure water into the first grouting pipe, and the high-pressure water seeps in the foundation at the bottom of the bored pile and flows into the third grouting pipe, and continues to flush the position at the bottom of the bored pile in the foundation, expands the cavity area, and the high-pressure water overflows from the third grouting pipe with the debris at the bottom of the bored pile until the third grouting pipe overflows with clear water, and then the high-pressure water pump is turned off;

[0019] Step 304, repeating steps 301 to 303 for multiple times until the first grouting pipe, the second grouting pipe and the third grouting pipe are all overflowing with clean water, and the hole cleaning is completed;

[0020] Step 4: High-pressure grouting. The process is as follows:

[0021] Step 401, open the first high-pressure pipe valve, the second high-pressure pipe valve and the third high-pressure pipe valve, install the grouting hose on the first grouting pipe, and inject high-pressure cement slurry into the first grouting pipe with a high-pressure grouting pump until the second grouting pipe and the third grouting pipe overflow with pure cement slurry, then remove the grouting hose on the first grouting pipe and install it on the second grouting pipe, and inject high-pressure cement slurry into the second grouting pipe until the first grouting pipe and the third grouting pipe overflow with pure cement slurry, then remove the grouting hose on the second grouting pipe and install it on the third grouting pipe, and inject high-pressure cement slurry into the third grouting pipe until the first grouting pipe and the second grouting pipe overflow with pure cement slurry;

[0022] Step 402, looping step 401 until high-pressure cement slurry is injected into any one grouting pipe and pure cement slurry overflows from the other two grouting pipes;

[0023] Step 403, close the second high-pressure pipe valve and the third high-pressure pipe valve, install the grouting hose on the first grouting pipe, and the high-pressure grouting pump injects high-pressure cement slurry into the first grouting pipe. When the amount of cement slurry injected into the first grouting pipe is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the first high-pressure pipe valve; open the second high-pressure pipe valve, discharge the high-pressure gas accumulated at the top of the second grouting pipe, install the grouting hose on the second grouting pipe, and inject the high-pressure cement slurry into the second grouting pipe. When the amount of cement slurry injected into the second grouting pipe is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the second high-pressure pipe valve; open the third high-pressure pipe valve, discharge the high-pressure gas accumulated at the top of the third grouting pipe, install the grouting hose on the third grouting pipe, and the high-pressure grouting pump injects high-pressure cement slurry into the third grouting pipe. When the amount of cement slurry injected into the third grouting pipe is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the third high-pressure pipe valve;

[0024] Step 404, repeating step 403 for multiple times until the gas in the grouting pipe is exhausted and the grouting volume is greater than the cement slurry volume threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, and the high-pressure grouting is completed;

[0025] Step 5, forming an enlarged head: high-pressure cement slurry flows into the void area through the reinforcement hole, compacts the void area, waits for the high-pressure cement in the void area to solidify, and the high-pressure cement solidified in the void area forms an enlarged head, waits for the high-pressure cement in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole to solidify, and the high-pressure cement solidified in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole respectively form a connecting column, and the connecting column and the enlarged head are connected as one.

[0026] The above method is characterized in that: in step three, the water pressure of the high-pressure water pump injecting high-pressure water into the first grouting pipe, the second grouting pipe and the third grouting pipe is 5MPa~10MPa.

[0027] The above method is characterized in that: in step 4, the pressure of the high-pressure cement slurry injected by the high-pressure grouting pump into the first grouting pipe, the second grouting pipe and the third grouting pipe is 5MPa to 10MPa.

[0028] The above method is characterized in that the cement slurry is ultrafine cement slurry, the particle size of ultrafine cement in the ultrafine cement slurry is 0.2μm to 20μm, and the average particle size of ultrafine cement in the ultrafine cement slurry is 5μm to 6μm.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. The structure adopted by the present invention is to set three reinforcement holes, and a grouting pipe is inserted at the top of each reinforcement hole. The grouting pipe only serves as a connecting piece for the high-pressure water pump and the high-pressure grouting pump to inject water or grout into the reinforcement hole, and does not penetrate into the bottom of the reinforcement hole, so as to avoid continuous pulling of the grouting pipe and continuous exhaust of the reinforcement hole during the grouting process. The bottom ends of the two reinforcement holes are flushed and connected by high-pressure water, and a cavity area is formed at the bottom of the bored pile in the foundation. The connectivity of the three reinforcement holes is used to realize the cleaning and grouting of the cavity area and the reinforcement hole, which has good circulation and is easy to promote and use.

[0031] 2. In the process of cleaning the hollow area and the three reinforcement holes in the structure adopted by the present invention, the soil and gravel around the hollow area in the foundation will be taken away, so that the reinforcement holes and the hollow area are thoroughly cleaned, and the cleaning effect is good.

[0032] 3. In the structure adopted by the present invention, the water injection pipe is coordinated with the grouting pipe through a high-pressure water pump, and the grouting hose is coordinated with the grouting pipe through a high-pressure grouting pump. The cement slurry injected into the grouting pipe by the grouting hose forms a connecting column, and the cement slurry flows into the cavity area through the reinforcement hole and forms an enlarged head. The high-pressure cement solidified in the connecting column and the enlarged head is connected as a whole, which effectively improves the bearing capacity of the bored pile, constructs the pile connection, and has little impact on the entire bored pile, short construction period, low cost, avoids a large amount of labor consumption, and has good safety.

[0033] 4. The method adopted by the present invention has simple steps. The method comprises the following steps: closing one high-pressure pipe valve and opening two high-pressure pipe valves, installing a water injection pipe on an opened grouting pipe, and injecting high-pressure water into the opened grouting pipe by a high-pressure water pump to forcibly flush the debris at the bottom of the bored pile, so that the two corresponding reinforcement holes opened by the high-pressure pipe valve are connected, and then the closed high-pressure pipe valve is replaced, and this process is repeated until all three grouting pipes overflow with clean water, and the bottom ends of the two reinforcement holes are flushed and connected by high-pressure water to form a cavity area at the bottom of the bored pile in the foundation; high-pressure grouting is then performed in the same manner, and the high-pressure cement in the cavity area is solidified, and the high-pressure cement solidified in the cavity area forms an enlarged head, and the high-pressure cement in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole are solidified, and the high-pressure cement solidified in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole respectively form a connecting column, and the connecting column and the enlarged head are connected as a whole, so as to effectively improve the bearing capacity of the bored pile.

[0034] To sum up, the present invention is novel and reasonable in design. Only three reinforcement holes are vertically drilled from the top to the bottom of the bored pile. The bottom ends of the two reinforcement holes are flushed and connected by high-pressure water, so that a cavity area is formed at the bottom of the bored pile in the foundation, and cleaning and grouting are completed. The circulation is good, and an enlarged head is formed in the cavity area after grouting, and it is integrally connected with the connecting column, which effectively improves the bearing capacity of the bored pile. The disturbance to the entire bored pile is small, the construction period is short, the cost is low, a large amount of labor consumption is avoided, the safety is good, and it is easy to promote and use.

[0035] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the borehole in the bored pile in the structure of the present invention.

[0037] Figure 2 It is a schematic diagram of the structure for cleaning the bottom of bored piles in the structure of the present invention.

[0038] Figure 3 It is a schematic diagram of the structure after grouting in the structure of the present invention.

[0039] Figure 4 The figure is a schematic diagram of the arrangement relationship of the first reinforcement hole, the second reinforcement hole and the third reinforcement hole at the top of the bored cast-in-place pile in the structure of the present invention.

[0040] Figure 5 The figure is a flowchart of the method of the present invention.

[0041] Description of the accompanying drawings: 1—foundation; 2—bored pile; 4—first reinforcement hole;

[0042] 5—second reinforcement hole; 6—third reinforcement hole; 7—first grouting pipe;

[0043] 8—second grouting pipe; 9—third grouting pipe; 10—first high-pressure pipe valve;

[0044] 11—second high-pressure pipe valve; 12—third high-pressure pipe valve; 13—sealing layer;

[0045] 14—water injection pipe; 15—high-pressure water pump; 16—cavitation area;

[0046] 17—enlarged head; 18—connecting column; 19—grouting hose;

[0047] 20—High-pressure grouting pump. DETAILED DESCRIPTION

[0048] like Figure 1 middle Figure 4As shown, a structure for improving the bearing capacity of a bored pile by drilling a hole in a pile according to the present invention comprises a first reinforcement hole 4, a second reinforcement hole 5 and a third reinforcement hole 6 vertically drilled from the top of the bored pile 2 to the bottom of the pile, the top of the first reinforcement hole 4 is provided with a first grouting pipe 7 extending into the first reinforcement hole 4, a first high-pressure pipe valve 10 is provided on the pipe section of the first grouting pipe 7 extending out of the first reinforcement hole 4, a second grouting pipe 8 extending into the second reinforcement hole 5 is provided at the top of the second reinforcement hole 5, a second high-pressure pipe valve 11 is provided on the pipe section of the second grouting pipe 8 extending out of the second reinforcement hole 5, a third grouting pipe 9 extending into the third reinforcement hole 6 is provided at the top of the third reinforcement hole 6, a third grouting pipe 9 extending into the third reinforcement hole 6 is provided on the pipe section of the third grouting pipe 9 extending out of the third reinforcement hole 6 The third high-pressure pipe valve 12, the gap between the first grouting pipe 7 and the first reinforcement hole 4, the gap between the second grouting pipe 8 and the second reinforcement hole 5, and the gap between the third grouting pipe 9 and the third reinforcement hole 6 are all sealed by the sealing layer 13, and a high-pressure water pump 15 and a high-pressure grouting pump 20 are arranged on the ground beside the bored pile 2. The water injection pipe 14 cooperates with the grouting pipe through the high-pressure water pump 15, and the grouting hose 19 cooperates with the grouting pipe through the high-pressure grouting pump 20. The position at the bottom of the bored pile 2 in the foundation 1 is flushed with high-pressure water to form a cavity area 16, and the cement slurry injected into the grouting pipe by the grouting hose 19 forms a connecting column 18. The cement slurry flows into the cavity area 16 through the reinforcement hole and forms an enlarged head 17 integrally connected with the connecting column 18.

[0049] It should be noted that by setting three reinforcement holes and inserting a grouting pipe at the top of each reinforcement hole, the grouting pipe only serves as a connecting piece for the high-pressure water pump and the high-pressure grouting pump to inject water or grouting into the reinforcement hole, and does not penetrate into the bottom of the reinforcement hole, so as to avoid continuous pulling of the grouting pipe and continuous exhaust of the reinforcement hole during the grouting process. The bottom ends of the two reinforcement holes are flushed and connected by high-pressure water, and a cavity area is formed at the bottom of the bored pile in the foundation. The connectivity of the three reinforcement holes is used to realize cleaning and grouting of the cavity area and the reinforcement holes, and the circulation is good. In the process of cleaning the cavity area and the three reinforcement holes, The soil and gravel around the cavity area in the foundation are walked through to achieve thorough cleaning of the reinforcement hole and the cavity area, with good cleaning effect; the water injection pipe is coordinated with the grouting pipe through a high-pressure water pump, and the grouting hose is coordinated with the grouting pipe through a high-pressure grouting pump. The cement slurry injected into the grouting pipe by the grouting hose forms a connecting column, and the cement slurry flows into the cavity area through the reinforcement hole to form an enlarged head. The high-pressure cement solidified in the connecting column and the enlarged head is connected as a whole, which effectively improves the bearing capacity of the bored pile, constructs the pile connection, has little impact on the entire bored pile, has a short construction period, low cost, avoids a large amount of labor consumption, and has good safety.

[0050] In this embodiment, the length of the first grouting pipe 7, the length of the second grouting pipe 8 and the length of the third grouting pipe 9 are all 50 cm to 100 cm.

[0051] It should be noted that the length of the first grouting pipe 7, the length of the second grouting pipe 8 and the length of the third grouting pipe 9 are all 50cm to 100cm. Their purpose is only to serve as connecting parts for the high-pressure water pump 15 and the high-pressure grouting pump 20 to inject water or grout into the reinforcement hole. Half of the grouting pipe extends into the reinforcement hole and is connected to the reinforcement hole to seal the reinforcement hole. The other half of the grouting pipe extends out of the reinforcement hole to install a high-pressure pipe valve.

[0052] In this embodiment, the first reinforcement holes 4 , the second reinforcement holes 5 and the third reinforcement holes 6 are evenly arranged in the bored pile 2 around the central axis of the bored pile 2 .

[0053] It should be noted that the first reinforcement hole 4, the second reinforcement hole 5 and the third reinforcement hole 6 are evenly arranged in the bored pile 2 around the central axis of the bored pile 2, so that the reinforcement holes can evenly clean the debris at the bottom of the bored pile, and the circulation is good.

[0054] In this embodiment, the diameters of the first reinforcement hole 4 , the second reinforcement hole 5 , and the third reinforcement hole 6 are all 8 cm to 10 cm.

[0055] It should be noted that the diameters of the first reinforcement hole 4 , the second reinforcement hole 5 and the third reinforcement hole 6 are all 8 cm to 10 cm. The openings are small, which has little impact on the entire bored pile and shortens the construction period.

[0056] In this embodiment, the cement slurry is ultrafine cement slurry, the particle size of ultrafine cement in the ultrafine cement slurry is 0.2 μm to 20 μm, and the average particle size of ultrafine cement in the ultrafine cement slurry is 5 μm to 6 μm.

[0057] It should be noted that the components contained in the ultrafine cement slurry and the weight ratio of each component are: 100 parts of ultrafine cement, 0.6-2.0 parts of fluid loss reducer, 0.05-0.3 parts of hydroxyl isocyanate diphosphate retarder, 0.4 parts of dispersant, 0.4 parts of tributyl phosphate defoamer, 76 parts of water, GM8000 ultrafine cement is used for the ultrafine cement, and DSJ-S fluid loss reducer is used for the fluid loss reducer. The ultrafine cement slurry is more likely to seal the void area at the bottom of the bored pile, and has good fluidity.

[0058] like Figure 5 A method for increasing the bearing capacity of a bored pile by drilling a hole in the pile is shown, comprising the following steps:

[0059] Step 1: Obtain reinforcement holes: a first reinforcement hole 4, a second reinforcement hole 5 and a third reinforcement hole 6 vertically drilled from the top to the bottom of the bored pile 2;

[0060] The diameters of the first reinforcement hole 4, the second reinforcement hole 5 and the third reinforcement hole 6 are all 8 cm to 10 cm;

[0061] The first reinforcement hole 4, the second reinforcement hole 5 and the third reinforcement hole 6 are evenly arranged in the bored pile 2 around the central axis of the bored pile 2;

[0062] Step 2, installing the grouting pipe and the high-pressure pipe valve: install the first grouting pipe 7 extending into the first reinforcement hole 4 at the top end of the first reinforcement hole 4, install the first high-pressure pipe valve 10 on the pipe section of the first grouting pipe 7 extending out of the first reinforcement hole 4, install the second grouting pipe 8 extending into the second reinforcement hole 5 at the top end of the second reinforcement hole 5, install the second high-pressure pipe valve 11 on the pipe section of the second grouting pipe 8 extending out of the second reinforcement hole 5, install the third grouting pipe 9 extending into the third reinforcement hole 6 at the top end of the third reinforcement hole 6, install the third high-pressure pipe valve 12 on the pipe section of the third grouting pipe 9 extending out of the third reinforcement hole 6, and the gap between the first grouting pipe 7 and the first reinforcement hole 4, the gap between the second grouting pipe 8 and the second reinforcement hole 5, and the gap between the third grouting pipe 9 and the third reinforcement hole 6 are all sealed by the sealing layer 13;

[0063] The length of the first grouting pipe 7, the length of the second grouting pipe 8 and the length of the third grouting pipe 9 are all 50 cm to 100 cm;

[0064] Step 3: High-pressure hole cleaning. The process is as follows:

[0065] Step 301, close the third high-pressure pipe valve 12, open the first high-pressure pipe valve 10 and the second high-pressure pipe valve 11, install the water injection pipe 14 on the first grouting pipe 7, and the high-pressure water pump 15 injects high-pressure water into the first grouting pipe 7. The high-pressure water seeps in the foundation 1 at the bottom of the bored pile 2 until it flows into the second grouting pipe 8, flushing the position at the bottom of the bored pile 2 in the foundation 1 to form a cavity area 16. The high-pressure water overflows from the second grouting pipe 8 with the debris at the bottom of the bored pile 2 until the second When the grouting pipe 8 overflows with clean water, the water injection pipe 14 on the first grouting pipe 7 is removed and installed on the second grouting pipe 8. The high-pressure water pump 15 injects high-pressure water into the second grouting pipe 8. The high-pressure water seeps into the second grouting pipe 8 in the foundation 1 at the bottom of the bored pile 2, and continues to flush the position at the bottom of the bored pile 2 in the foundation 1, expanding the cavity area 16. The high-pressure water overflows from the first grouting pipe 7 with the slag at the bottom of the bored pile 2 until the first grouting pipe 7 overflows with clean water, and the high-pressure water pump 15 is turned off;

[0066] Step 302, close the first high-pressure pipe valve 10, open the third high-pressure pipe valve 12 and the second high-pressure pipe valve 11, install the water injection pipe 14 on the second grouting pipe 8, and the high-pressure water pump 15 injects high-pressure water into the second grouting pipe 8. The high-pressure water seeps in the foundation 1 at the bottom of the bored pile 2 until it flows into the third grouting pipe 9, flushes the position at the bottom of the bored pile 2 in the foundation 1, expands the cavity area 16, and the high-pressure water overflows from the third grouting pipe 9 with the debris at the bottom of the bored pile 2 until the third The grouting pipe 9 overflows with clean water, the water injection pipe 14 on the second grouting pipe 8 is removed and installed on the third grouting pipe 9, and the high-pressure water pump 15 injects high-pressure water into the third grouting pipe 9. The high-pressure water seeps into the second grouting pipe 8 in the foundation 1 at the bottom of the bored pile 2, and continues to flush the position at the bottom of the bored pile 2 in the foundation 1, expanding the cavity area 16, and the high-pressure water overflows from the second grouting pipe 8 with the slag at the bottom of the bored pile 2 until the second grouting pipe 8 overflows with clean water, and the high-pressure water pump 15 is turned off;

[0067] Step 303, close the second high-pressure pipe valve 11, open the first high-pressure pipe valve 10 and the third high-pressure pipe valve 12, install the water injection pipe 14 on the third grouting pipe 9, and the high-pressure water pump 15 injects high-pressure water into the third grouting pipe 9. The high-pressure water seeps in the foundation 1 at the bottom of the bored pile 2 until it flows into the first grouting pipe 7, flushes the position at the bottom of the bored pile 2 in the foundation 1, expands the cavity area 16, and the high-pressure water overflows from the first grouting pipe 7 with the debris at the bottom of the bored pile 2 until the first When the grouting pipe 7 overflows with clean water, the water injection pipe 14 on the third grouting pipe 9 is removed and installed on the first grouting pipe 7. The high-pressure water pump 15 injects high-pressure water into the first grouting pipe 7. The high-pressure water seeps into the foundation 1 at the bottom of the bored pile 2 and flows into the third grouting pipe 9, continuing to flush the position at the bottom of the bored pile 2 in the foundation 1, expanding the cavity area 16, and the high-pressure water overflows from the third grouting pipe 9 with the slag at the bottom of the bored pile 2 until the third grouting pipe 9 overflows with clean water, and the high-pressure water pump 15 is turned off;

[0068] Step 304, repeating steps 301 to 303 for multiple times until the first grouting pipe 7, the second grouting pipe 8 and the third grouting pipe 9 are all overflowed with clean water, and the hole cleaning is completed;

[0069] Step 4: High-pressure grouting. The process is as follows:

[0070] Step 401, open the first high-pressure pipe valve 10, the second high-pressure pipe valve 11 and the third high-pressure pipe valve 12, install the grouting hose 19 on the first grouting pipe 7, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the first grouting pipe 7 until the second grouting pipe 8 and the third grouting pipe 9 overflow with pure cement slurry, then remove the grouting hose 19 on the first grouting pipe 7 and install it on the second grouting pipe 8, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the second grouting pipe 8 until the first grouting pipe 7 and the third grouting pipe 9 overflow with pure cement slurry, then remove the grouting hose 19 on the second grouting pipe 8 and install it on the third grouting pipe 9, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the third grouting pipe 9 until the first grouting pipe 7 and the second grouting pipe 8 overflow with pure cement slurry;

[0071] Step 402, looping step 401 until high-pressure cement slurry is injected into any one grouting pipe and pure cement slurry overflows from the other two grouting pipes;

[0072] It should be noted that before grouting, the three high-pressure pipe valves are opened to drain the water in the three reinforcement holes and the cavity area 16 until high-pressure cement slurry is injected into any grouting pipe and the other two grouting pipes overflow with pure cement slurry, resulting in good drainage effect.

[0073] Step 403, close the second high-pressure pipe valve 11 and the third high-pressure pipe valve 12, install the grouting hose 19 on the first grouting pipe 7, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the first grouting pipe 7. When the amount of cement slurry injected into the first grouting pipe 7 is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the first high-pressure pipe valve 10; open the second high-pressure pipe valve 11, and the high-pressure gas accumulated at the top of the second grouting pipe 8 is discharged, install the grouting hose 19 on the second grouting pipe 8, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the second grouting pipe 8. High-pressure cement slurry: when the amount of cement slurry injected into the second grouting pipe 8 is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the second high-pressure pipe valve 11; open the third high-pressure pipe valve 12, and the high-pressure gas accumulated at the top of the third grouting pipe 9 is discharged. The grouting hose 19 is installed on the third grouting pipe 9, and the high-pressure grouting pump 20 injects high-pressure cement slurry into the third grouting pipe 9. When the amount of cement slurry injected into the third grouting pipe 9 is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the third high-pressure pipe valve 12;

[0074] Step 404, repeating step 403 for multiple times until the gas in the grouting pipe is exhausted and the grouting volume is greater than the cement slurry volume threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, and the high-pressure grouting is completed;

[0075] Step 5, forming an enlarged head: high-pressure cement slurry flows into the cavity area 16 through the reinforcement hole, compacts the cavity area 16, waits for the high-pressure cement in the cavity area 16 to solidify, and the high-pressure cement solidified in the cavity area 16 forms an enlarged head 17, waits for the high-pressure cement in the first reinforcement hole 4, the second reinforcement hole 5 and the third reinforcement hole 6 to solidify, and the high-pressure cement solidified in the first reinforcement hole 4, the second reinforcement hole 5 and the third reinforcement hole 6 respectively form a connecting column 18, and the connecting column 18 and the enlarged head 17 are connected as a whole.

[0076] In this embodiment, in step three, the water pressure of the high-pressure water injected by the high-pressure water pump 15 into the first grouting pipe 7, the second grouting pipe 8 and the third grouting pipe 9 is 5MPa to 10MPa.

[0077] In this embodiment, in step 4, the pressure of the high-pressure cement slurry injected by the high-pressure grouting pump 20 into the first grouting pipe 7, the second grouting pipe 8 and the third grouting pipe 9 is 5MPa to 10MPa.

[0078] In this embodiment, the cement slurry is ultrafine cement slurry, the particle size of ultrafine cement in the ultrafine cement slurry is 0.2 μm to 20 μm, and the average particle size of ultrafine cement in the ultrafine cement slurry is 5 μm to 6 μm.

[0079] When the present invention is used, one high-pressure pipe valve is closed, two high-pressure pipe valves are opened, a water injection pipe is installed on an opened grouting pipe, a high-pressure water pump injects high-pressure water into the opened grouting pipe, and the slag at the bottom of the bored pile is forcibly flushed, so that the two corresponding reinforcement holes opened by the high-pressure pipe valve are connected, and then the closed high-pressure pipe valve is replaced, and this process is repeated until all three grouting pipes overflow with clean water, and the bottom ends of the two reinforcement holes are flushed and connected by high-pressure water, so that a cavity area is formed at the position of the bottom of the bored pile in the foundation; then Through high-pressure grouting in the same way, the high-pressure cement in the void area is solidified, and the high-pressure cement solidified in the void area forms an enlarged head. After the high-pressure cement in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole is solidified, the high-pressure cement solidified in the first reinforcement hole, the second reinforcement hole and the third reinforcement hole respectively form a connecting column, and the connecting column and the enlarged head are connected as a whole, which effectively improves the bearing capacity of the bored pile, and has little disturbance to the entire bored pile, short construction period, low cost, avoids a large amount of labor consumption, and has good safety.

[0080] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for improving the bearing capacity of a bored pile by drilling holes in a pile, wherein the method utilizes a structure for improving the bearing capacity of a bored pile by drilling holes in a pile to improve the bearing capacity of a bored pile, and the method is characterized in that: The structure for drilling holes in a pile to improve the bearing capacity of a bored cast-in-place pile comprises a first reinforcement hole (4), a second reinforcement hole (5) and a third reinforcement hole (6) vertically drilled from the top of the bored cast-in-place pile (2) to the bottom of the pile, a first grouting pipe (7) extending into the first reinforcement hole (4) being installed at the top end of the first reinforcement hole (4), a first high-pressure pipe valve (10) being installed on the pipe section of the first grouting pipe (7) extending out of the first reinforcement hole (4), a second grouting pipe (8) extending into the second reinforcement hole (5) being installed at the top end of the second reinforcement hole (5), a second high-pressure pipe valve (11) being installed on the pipe section of the second grouting pipe (8) extending out of the second reinforcement hole (5), a third grouting pipe (9) extending into the third reinforcement hole (6) being installed at the top end of the third reinforcement hole (6), a third high-pressure pipe valve (12) being installed on the pipe section of the third grouting pipe (9) extending out of the third reinforcement hole (6) 12), the gap between the first grouting pipe (7) and the first reinforcement hole (4), the gap between the second grouting pipe (8) and the second reinforcement hole (5), and the gap between the third grouting pipe (9) and the third reinforcement hole (6) are all sealed by a sealing layer (13), a high-pressure water pump (15) and a high-pressure grouting pump (20) are arranged on the ground beside the bored pile (2), the water injection pipe (14) cooperates with the grouting pipe through the high-pressure water pump (15), and the grouting hose (19) cooperates with the grouting pipe through the high-pressure grouting pump (20), a cavity area (16) is formed at the position of the bottom of the bored pile (2) in the foundation (1) by high-pressure water flushing, cement slurry injected into the grouting pipe by the grouting hose (19) forms a connecting column (18), and the cement slurry flows into the cavity area (16) through the reinforcement hole and forms an enlarged head (17) integrally connected to the connecting column (18); The method comprises the following steps: Step 1, obtaining reinforcement holes: a first reinforcement hole (4), a second reinforcement hole (5) and a third reinforcement hole (6) vertically drilled from the top to the bottom of the bored pile (2); The diameters of the first reinforcement hole (4), the second reinforcement hole (5) and the third reinforcement hole (6) are all 8 cm to 10 cm; The first reinforcement hole (4), the second reinforcement hole (5) and the third reinforcement hole (6) are evenly arranged in the bored pile (2) around the central axis of the bored pile (2); Step 2: Install the grouting pipe and the high-pressure pipe valve: install the first grouting pipe (7) extending into the first reinforcement hole (4) at the top end of the first reinforcement hole (4), install the first high-pressure pipe valve (10) on the pipe section of the first grouting pipe (7) extending out of the first reinforcement hole (4), install the second grouting pipe (8) extending into the second reinforcement hole (5) at the top end of the second reinforcement hole (5), and install the second high-pressure pipe valve (11) on the pipe section of the second grouting pipe (8) extending out of the second reinforcement hole (5). ), a third grouting pipe (9) extending into the third reinforcement hole (6) is installed at the top end of the third reinforcement hole (6), a third high-pressure pipe valve (12) is installed on the pipe section of the third grouting pipe (9) extending out of the third reinforcement hole (6), and the gap between the first grouting pipe (7) and the first reinforcement hole (4), the gap between the second grouting pipe (8) and the second reinforcement hole (5), and the gap between the third grouting pipe (9) and the third reinforcement hole (6) are all sealed by a sealing layer (13); The length of the first grouting pipe (7), the length of the second grouting pipe (8) and the length of the third grouting pipe (9) are all 50 cm to 100 cm; Step 3: High-pressure hole cleaning. The process is as follows: Step 301, close the third high-pressure pipe valve (12), open the first high-pressure pipe valve (10) and the second high-pressure pipe valve (11), install the water injection pipe (14) on the first grouting pipe (7), and use the high-pressure water pump (15) to inject high-pressure water into the first grouting pipe (7). The high-pressure water seeps into the foundation (1) at the bottom of the bored pile (2) until it flows into the second grouting pipe (8), flushes the position at the bottom of the bored pile (2) in the foundation (1), and forms a cavity area (16). The high-pressure water carries the debris at the bottom of the bored pile (2) from the second grouting pipe (8) until the second grouting pipe (8) overflows. When the grouting pipe (8) overflows with clean water, the water injection pipe (14) on the first grouting pipe (7) is removed and installed on the second grouting pipe (8), and the high-pressure water pump (15) injects high-pressure water into the second grouting pipe (8). The high-pressure water seeps into the foundation (1) at the bottom of the bored pile (2) and flows into the second grouting pipe (8), continuing to flush the position at the bottom of the bored pile (2) in the foundation (1), expanding the cavity area (16), and the high-pressure water overflows from the first grouting pipe (7) with the debris at the bottom of the bored pile (2), until the first grouting pipe (7) overflows with clean water, and the high-pressure water pump (15) is turned off; Step 302, close the first high-pressure pipe valve (10), open the third high-pressure pipe valve (12) and the second high-pressure pipe valve (11), install the water injection pipe (14) on the second grouting pipe (8), and use the high-pressure water pump (15) to inject high-pressure water into the second grouting pipe (8). The high-pressure water seeps into the foundation (1) at the bottom of the bored pile (2) until it flows into the third grouting pipe (9), flushes the position at the bottom of the bored pile (2) in the foundation (1), expands the cavity area (16), and the high-pressure water overflows from the third grouting pipe (9) with the debris at the bottom of the bored pile (2) until the third grouting pipe (9) is filled with water. When the grouting pipe (9) overflows with clean water, the water injection pipe (14) on the second grouting pipe (8) is removed and installed on the third grouting pipe (9), and the high-pressure water pump (15) injects high-pressure water into the third grouting pipe (9). The high-pressure water seeps into the second grouting pipe (8) in the foundation (1) at the bottom of the bored pile (2), and continues to flush the position at the bottom of the bored pile (2) in the foundation (1), expanding the cavity area (16). The high-pressure water carries the debris at the bottom of the bored pile (2) and overflows from the second grouting pipe (8), until the second grouting pipe (8) overflows with clean water, and the high-pressure water pump (15) is turned off; Step 303, close the second high-pressure pipe valve (11), open the first high-pressure pipe valve (10) and the third high-pressure pipe valve (12), install the water injection pipe (14) on the third grouting pipe (9), and use the high-pressure water pump (15) to inject high-pressure water into the third grouting pipe (9). The high-pressure water seeps into the foundation (1) at the bottom of the bored pile (2) until it flows into the first grouting pipe (7), flushes the position at the bottom of the bored pile (2) in the foundation (1), expands the cavity area (16), and the high-pressure water carries the debris at the bottom of the bored pile (2) from the first grouting pipe (7) until the first grouting pipe (7) overflows. When the grouting pipe (7) overflows with clean water, the water injection pipe (14) on the third grouting pipe (9) is removed and installed on the first grouting pipe (7), and the high-pressure water pump (15) injects high-pressure water into the first grouting pipe (7). The high-pressure water seeps through the foundation (1) at the bottom of the bored pile (2) and flows into the third grouting pipe (9), continuing to flush the position at the bottom of the bored pile (2) in the foundation (1), expanding the cavity area (16), and the high-pressure water carries the debris at the bottom of the bored pile (2) and overflows from the third grouting pipe (9), until the third grouting pipe (9) overflows with clean water, and the high-pressure water pump (15) is turned off; Step 304, repeating steps 301 to 303 for multiple times until the first grouting pipe (7), the second grouting pipe (8) and the third grouting pipe (9) are all overflowing with clean water, and the hole cleaning is completed; Step 4: High-pressure grouting. The process is as follows: Step 401, opening the first high-pressure pipe valve (10), the second high-pressure pipe valve (11) and the third high-pressure pipe valve (12), installing the grouting hose (19) on the first grouting pipe (7), and injecting high-pressure cement slurry into the first grouting pipe (7) by the high-pressure grouting pump (20) until the second grouting pipe (8) and the third grouting pipe (9) overflow with pure cement slurry, then removing the grouting hose (19) on the first grouting pipe (7) and installing it on the second grouting pipe (8), and injecting high-pressure cement slurry into the second grouting pipe (8) until the first grouting pipe (7) and the third grouting pipe (9) overflow with pure cement slurry, then removing the grouting hose (19) on the second grouting pipe (8) and installing it on the third grouting pipe (9), and injecting high-pressure cement slurry into the third grouting pipe (9) until the first grouting pipe (7) and the second grouting pipe (8) overflow with pure cement slurry; Step 402, looping step 401 until high-pressure cement slurry is injected into any one grouting pipe and pure cement slurry overflows from the other two grouting pipes; Step 403, close the second high-pressure pipe valve (11) and the third high-pressure pipe valve (12), install the grouting hose (19) on the first grouting pipe (7), and use the high-pressure grouting pump (20) to inject high-pressure cement slurry into the first grouting pipe (7). When the amount of cement slurry injected into the first grouting pipe (7) is greater than the cement slurry amount threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, close the first high-pressure pipe valve (10); open the second high-pressure pipe valve (11), discharge the high-pressure gas accumulated at the top of the second grouting pipe (8), install the grouting hose (19) on the second grouting pipe (8), and use the high-pressure grouting pump (20) to inject high-pressure cement slurry into the second grouting pipe (8). ) and when the amount of cement slurry injected into the second grouting pipe (8) is greater than a cement slurry amount threshold or the grouting pressure is greater than a grouting pressure threshold or the ground is reversed, the second high-pressure pipe valve (11) is closed; the third high-pressure pipe valve (12) is opened to discharge the high-pressure gas accumulated at the top of the third grouting pipe (9), the grouting hose (19) is installed on the third grouting pipe (9), and the high-pressure grouting pump (20) injects high-pressure cement slurry into the third grouting pipe (9); when the amount of cement slurry injected into the third grouting pipe (9) is greater than a cement slurry amount threshold or the grouting pressure is greater than a grouting pressure threshold or the ground is reversed, the third high-pressure pipe valve (12) is closed; Step 404, repeating step 403 for multiple times until the gas in the grouting pipe is exhausted and the grouting volume is greater than the cement slurry volume threshold or the grouting pressure is greater than the grouting pressure threshold or the ground is reversed, and the high-pressure grouting is completed; Step 5, forming an enlarged head: high-pressure cement slurry flows into the cavity area (16) through the reinforcement hole, and the cavity area (16) is compacted. After the high-pressure cement in the cavity area (16) solidifies, the high-pressure cement solidified in the cavity area (16) forms an enlarged head (17). After the high-pressure cement in the first reinforcement hole (4), the second reinforcement hole (5) and the third reinforcement hole (6) solidify, the high-pressure cement solidified in the first reinforcement hole (4), the second reinforcement hole (5) and the third reinforcement hole (6) respectively form a connecting column (18), and the connecting column (18) and the enlarged head (17) are connected as a whole.

2. The method for improving the bearing capacity of bored piles by drilling holes in piles according to claim 1, characterized in that: In step 3, the high-pressure water pump (15) injects high-pressure water into the first grouting pipe (7), the second grouting pipe (8) and the third grouting pipe (9) at a water pressure of 5 MPa to 10 MPa.

3. The method for improving the bearing capacity of bored piles by drilling holes in piles according to claim 1, characterized in that: In step 4, the high-pressure grouting pump (20) injects high-pressure cement slurry into the first grouting pipe (7), the second grouting pipe (8) and the third grouting pipe (9) at a pressure of 5 MPa to 10 MPa.

4. The method for improving the bearing capacity of bored piles by drilling holes in piles according to claim 1, characterized in that: The cement slurry is ultrafine cement slurry, the particle size of ultrafine cement in the ultrafine cement slurry is 0.2 μm to 20 μm, and the average particle size of ultrafine cement in the ultrafine cement slurry is 5 μm to 6 μm.

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