Construction system of cement-soil mixing stiff composite pile

Abstract

The construction system comprises a rotary joint, a pile body connector and a special-shaped pipe pile which are detachably connected together in sequence, and the rotary joint is used for being connected to a power head of a rotary pile machine; a regular polygon-shaped driving hole with an upward opening is formed in a pile body of the special-shaped pipe pile, a connecting bolt and a grouting pipe are pre-buried in the pile body, a guniting hole is formed in the pile end, one end of the grouting pipe upwards penetrates through the upper end face of the pile head, and the other end of the grouting pipe is communicated with the guniting hole. A stirring blade is further arranged at the pile end; the rotary joint is provided with a liquid inlet and a liquid outlet which are communicated with each other, the liquid inlet is used for being communicated with grouting equipment, and the liquid outlet is detachably communicated with a grouting pipe. According to the construction method, sinking of the special-shaped pipe pile and construction of the cement-soil mixing pile can be completed at a time, it is guaranteed that the cement-soil mixing pile and the special-shaped pipe pile are concentric, and the soil squeezing effect is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to a construction system of cement soil mixing stiff composite pile. BACKGROUND

[0002] Because the fishing pond, mudflat and the like are mostly soft soil foundation with large depth, low strength and large deformation, when the conventional prestressed concrete pipe pile is used as the foundation, the pipe pile with large diameter and long length is needed, which leads to large construction difficulty and high cost. The cement soil reinforced pile is a new type of stiff composite pile, which is firstly formed by the cement soil pile, and then the small diameter concrete pile is pressed into the cement soil pile as the pile core to form the cement soil reinforced pile.

[0003] The cement soil reinforced pile has large pile-soil extruded interface, which improves the load transmission path and presents the characteristics of the friction pile, so that the cement soil pile has much higher side resistance than the concrete pile, and the concrete pile has much higher pile body strength than the cement soil pile, and the combination of the two can obtain the cost performance higher than the traditional pile type. At present, the cement soil reinforced pile still has the following problems: the cement soil pile and the pile core insertion are two different construction processes, which need multiple equipment cross operation during construction, leading to many construction procedures, complicated construction, long construction period and high cost; the soil extrusion problem is prone to occur during the insertion of the concrete pile, leading to the damage of the adjacent pile and the adjacent building; during the construction process, it is difficult to ensure that the concrete pile is inserted along the pile core of the cement soil pile, resulting in the eccentricity of the concrete pile and the cement soil pile, which greatly reduces the bearing capacity of the cement soil reinforced pile. The above problems are particularly serious during the construction in the fishing pond, mudflat and the like. Therefore, it still has strong practical significance to improve the construction process of the cement soil reinforced pile in the fishing pond, mudflat and the like soft soil foundation area. CONTENT OF THE UTILITY MODEL

[0004] In order to solve the problems in the prior art, such as the need to use two different construction processes during the construction of the cement soil reinforced pile, leading to complicated construction, long construction period and high cost, and the eccentricity of the concrete pile and the cement soil pile, the utility model provides a construction system of cement soil mixing stiff composite pile, which comprises a rotary joint, a pile body connector and a special-shaped pipe pile which are sequentially and detachably connected together, the rotary joint is used to be connected to the power head of a rotary pile machine, and the rotary pile machine is used to drive the special-shaped pipe pile to rotate and sink.

[0005] The special-shaped pipe pile comprises a circular pile body, opposite ends of the pile body are formed into a pile head and a pile end respectively, the pile head faces upward, and the pile end faces downward; a driving hole is arranged in the pile body, the driving hole penetrates the end surface of the pile head in the vertical direction, the driving hole is a regular polygon, and the driving hole is coaxially arranged with the pile body; a connecting bolt and a grouting pipe are embedded in the pile body, the connecting bolt extends out of the end surface of the pile head in the vertical direction, a jet grouting hole is arranged at the pile end, one end of the grouting pipe penetrates the upper end surface of the pile head upward, and the other end of the grouting pipe is communicated with the jet grouting hole; a stirring blade is further arranged at the pile end; and the special-shaped pipe pile is a prestressed pipe pile.

[0006] The rotary joint has a liquid inlet and a liquid outlet that are in communication with each other, the liquid inlet is used for connecting the grouting equipment, and the liquid outlet is detachably connected with the grouting pipe.

[0007] When the construction system in the application is used to construct the cement-soil mixing and reinforced composite pile, the drilling of the special-shaped pipe pile and the construction of the cement-soil mixing pile are performed synchronously, the construction efficiency is improved, and the height of the cement-soil mixing pile and the special-shaped pipe pile can be ensured to be concentric. Compared with the reinforced composite pile formed by the conventional post-insertion method of the prestressed concrete pipe pile, the special-shaped pipe pile does not have the damage caused by the soil squeezing effect. The formed cement-soil mixing and reinforced composite pile comprises the special-shaped pipe pile and the cement-soil mixing pile wrapped around the special-shaped pipe pile, the cement-soil mixing pile is used to achieve the reinforcing effect, and the pile end resistance and the pile side friction are improved.

[0008] During construction, the special-shaped pipe pile is rotated and implanted into the cement-soil pile body instead of being sunk under the traditional static pressure, so the requirement for the bearing capacity of the construction site is relatively low, the surface soil layer does not need to be treated in advance, and the site is easy to construct in new filling soil, silt soil and waterlogged site. Therefore, for the soft foundation in the fish-light complementary and beach photovoltaic projects, the pile foundation bearing capacity, especially the compressive bearing capacity, can be effectively improved, and the length of the pile foundation can be shortened, thereby effectively improving the economy of the project.

[0009] After the special-shaped pipe pile is implanted into the soil layer in the rotating mode, the solidification contact area between the pile body and the cement-soil layer is increased, and the stirring blade located at the lower end of the pile body can greatly improve the vertical compressive and uplift capacities of the pile foundation.

[0010] Further, the pile body has a central hole extending in the vertical direction, the central hole is communicated with the driving hole, and one end of the central hole facing the pile end is a closed end. After the central hole is arranged, the weight of the special-shaped pipe pile can be reduced, the amount of cement and other raw materials can be reduced, and the manufacturing cost of the special-shaped pipe pile can be reduced. The pile body can be directly manufactured by using the existing pipe pile construction process.

[0011] Further, in order to more smoothly use the existing pipe pile production process, the central hole is circular.

[0012] Specifically, the rotary joint comprises an inner tube and an outer tube coaxially sleeved together, both of which extend along a vertical direction, both ends of the outer tube are rotatably connected to the inner tube through bearings, an annular cavity is formed between the inner tube and the outer tube, the inner tube has a liquid inlet hole on its tube wall, which communicates with the annular cavity and the inner cavity of the inner tube, and the outer tube has a liquid inlet opening which communicates with the annular cavity;

[0013] A connecting lug is arranged on the outer tube, which is fixedly connected to a fixed part of the rotary pile machine; one end of the inner tube is detachably connected to an output shaft of the power head, the other end of the inner tube is connected to the pile body connector through a bolt, and the inner cavity of the inner tube is formed into a liquid outlet opening at the end facing the pile body connector. With the rotary joint, the cement slurry can be smoothly introduced into the grouting pipe of the special-shaped tubular pile and sprayed outwards through the jetting hole.

[0014] Further, in order to improve the sealing performance of the rotary joint and avoid the cement slurry entering the bearing between the inner tube and the outer tube and accelerating the wear of the bearing, an upper sealing ring and a lower sealing ring are installed in the annular cavity, the upper sealing ring is located above the lower sealing ring, the upper sealing ring is used to seal the upper end of the annular cavity, and the lower sealing ring is used to seal the lower end of the annular cavity; in the vertical direction, the liquid inlet hole and the liquid inlet opening are located between the upper sealing ring and the lower sealing ring.

[0015] Specifically, the pile body connector comprises a rod body and a rod body flange, the rod body extends along a vertical direction, the rod body flange is fixedly arranged on the middle part of the rod body, the rod body flange divides the rod body into a slurry outlet part and a driving part, and the slurry outlet part is located above the driving part; an end flange is fixedly arranged on the top end of the slurry outlet part, and a slurry passing hole is arranged in the slurry outlet part, the slurry passing hole penetrates the top end surface of the rod body along the vertical direction, and the liquid outlet opening of the rotary joint communicates with the grouting pipe through the slurry passing hole; the pile body connector is connected to the rotary joint through the end flange;

[0016] The driving part has an outer periphery surface which is the same as the inner periphery surface of the driving hole, the pile body connector is arranged on the pile head of the special-shaped tubular pile through the rod body flange, the driving part is inserted into the driving hole, and the special-shaped tubular pile can be driven to rotate.

[0017] Since the driving part of the rod body has the same shape as the driving hole, a larger driving force can be transmitted, the driving force transmitted by the rotary joint can be applied to the pile body to drive the special-shaped tubular pile to rotate and sink, the rod body flange mainly plays a role of lifting the special-shaped tubular pile, and of course the rod body flange also has the role of transmitting the driving force.

[0018] This invention utilizes a drive unit to avoid the need for the piling machine to clamp the irregularly shaped pipe piles during driving. When constructing pipe piles using static pressure driving, a clamping method is required, necessitating a large clamping force from the piling machine. In actual construction, excessive clamping force is often used, easily causing cracks in the pipe pile, and in severe cases, crushing the pile and wasting it. Simply using downward pressure or hammering to drive the pipe pile can easily lead to tilting and breakage. This application utilizes the cooperation between the drive unit and the drive hole to transmit downward pressure and torque stably, ensuring uniform stress on the pile body. The mixing action of the stirring blades reduces the downward pressure during the driving of the irregularly shaped pipe pile.

[0019] Furthermore, in order to smoothly deliver cement grout into the grouting pipe, a grout hole is provided on the outer wall of the grout passage hole to connect to the grout passage hole, and a through-pipe hole is provided on the rod flange. One end of the outer pipe is connected to the grout passage hole, and the other end of the outer pipe passes through the through-pipe hole and is connected to the grouting pipe.

[0020] Furthermore, for ease of operation and work, the connecting lug is detachably attached to the housing of the power head. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of one embodiment of the irregular-shaped pipe pile in the application.

[0022] Figure 2 yes Figure 1 Top view.

[0023] Figure 3 yes Figure 1 A view from the center AA direction.

[0024] Figure 4 This is a diagram showing the construction status of cement-soil mixing stiffened composite piles.

[0025] Figure 5 yes Figure 4 Enlarged view of section B.

[0026] Figure 6 This is a schematic diagram of a pipe pile connector.

[0027] Figure 7 yes Figure 6 Top view.

[0028] Figure 8 yes Figure 6 The view of CC.

[0029] Figure 9 This is a schematic diagram of the rotary joint. Detailed Implementation

[0030] The construction system of the cement-soil mixing and reinforced composite pile in the present application is described below, please refer to Figures 1-9 , which comprises a swivel joint 30, a pile body joint 20 and a special-shaped pipe pile 10 connected together in sequence and detachably, the swivel joint 30 is used for connecting to the power head 51 of a rotary pile machine 90. For clear description, the structure of the special-shaped pipe pile 10 is described first below, please refer to Figures 1-3 , the direction of the arrow Z in the drawing indicates the vertical direction. The rotary pile machine can also be called a rotary pile driver.

[0031] The special-shaped pipe pile 10 is a prestressed pipe pile, which comprises a pile body 11 in a circular shape, the opposite ends of the pile body are formed into a pile head 111 and a pile end 112 respectively, the pile head 111 faces upward, and the pile end 112 faces downward. The central axis 113 of the pile body 11 extends along the vertical direction, and has a driving hole 121 in the pile body, the driving hole 121 penetrates the end face of the pile head upward along the vertical direction, the driving hole is square, and the driving hole is coaxially arranged with the pile body. It can be understood that in other embodiments, the driving hole can also be in the shape of an equilateral triangle, an equilateral hexagon, etc. The pile flange 17 is prefabricated at the end of the pile head 111 of the pile body 11 according to the conventional design.

[0032] The connecting bolt 14 and the grouting pipe 13 are pre-embedded in the pile body, the connecting bolt 14 extends upward along the vertical direction out of the upper end face of the pile flange, the grouting pipe 13 penetrates the end face of the pile head upward along the vertical direction, and the other end of the grouting pipe communicates with the grouting hole 16. The grouting hole penetrates the outer surface of the pile body outward, and the cement slurry entering the grouting pipe can be sprayed outward through the grouting hole.

[0033] The slurry pipe hole 171 is formed on the pile flange, the grouting pipe is opposite to the slurry pipe hole, and the slurry pipe hole is used for connecting the grouting pipe through external pipelines, so that the cement slurry can enter the grouting pipe. The stirring blade 15 is also provided at the pile end, in the present embodiment, a steel plate is pre-embedded in the pile end, and the stirring blade is a steel piece, which is welded on the pre-embedded steel plate after the production of the pile body is completed.

[0034] The pile body 11 has a central hole 12 extending along the vertical direction, the central hole 12 communicates with the driving hole 121, and the end of the central hole facing the pile end is a closed end. That is, the lower end of the central hole is a closed end, and the upper end is an open end. In the present embodiment, the central hole 12 is circular and coaxially arranged with the driving hole 121.

[0035] Please refer to Figure 4 , the output shaft of the power head 51 of the rotary pile machine 90 is bolted to the swivel joint through the adapter 52, and the power head 51 is carried by the rotary pile machine itself, which is a mature technology and will not be described in detail. Figure 4 , the mark 100 represents the ground.

[0036] Referring to Figure 9 In this embodiment, the rotary joint 30 comprises an inner tube 31 and an outer tube 32 rotatably sleeved on the outer periphery of the inner tube 31. An upper step surface 314 and a lower step surface 313 are provided on the outer peripheral surface of the inner tube 31. The upper step surface and the lower step surface are both formed by radially recessing the outer peripheral surface of the inner tube, wherein the upper step surface is located above the lower step surface, and both the upper step surface and the lower step surface are upward. The inner ring of the lower angular contact bearing 331 is supported on the lower step surface, and the inner ring of the upper angular contact bearing 332 is supported on the upper step surface. A pressing ring 351 is sleeved on the inner tube and screwed with a locking nut 352, the pressing ring 351 is pressed against the upper surface of the inner ring of the upper angular contact bearing, and the locking nut tightly presses the inner ring of the upper angular contact bearing on which the pressing ring 351 is tightly pressed. The upper end cover 342 is bolted to the upper end of the outer tube 32 and abuts against the lower surface of the outer ring of the upper angular contact bearing.

[0037] An annular cavity 323 is formed between the inner tube and the outer tube. To avoid the cement slurry entering the gap of the upper angular contact bearing and the lower angular contact bearing, an upper sealing ring 362 and a lower sealing ring 361 are installed in the annular cavity, wherein the upper sealing ring 362 is located above the lower sealing ring 361. The inner wall of the inner tube 31 has a liquid inlet hole 312 which communicates the annular cavity with the inner cavity 311 of the inner tube, and the outer tube 32 has a liquid inlet 321 which communicates the annular cavity, and the slurry inlet pipe 322 is welded on the outer tube and communicates the liquid inlet 321. In the vertical direction, the liquid inlet hole and the liquid inlet are located between the upper sealing ring and the lower sealing ring.

[0038] The outer tube is provided with a connecting lug 324 which is fixedly connected to the fixed part of the rotary pile machine. Specifically, in this embodiment, the connecting lug 324 is connected to the shell of the power head 51 through a connecting plate 325, and the two ends of the connecting plate are bolted to the connecting lug and the shell of the power head 51 respectively, so that the connecting lug is detachably connected to the shell of the power head.

[0039] The upper flange 372 is detachably installed on the top of the inner tube by the upper bolt 3721, and the lower flange 371 is welded on the bottom of the inner tube. The inner cavity of the inner tube is formed as a liquid outlet 315 towards the end of the pile connector.

[0040] Referring to Figures 6-8In the embodiment, the pile connector 20 is made of steel structure, and specifically includes a rod body 21 and a rod flange 25. The rod body extends in vertical direction, and the rod flange is fixed at the middle part of the rod body in vertical direction. The rod flange 25 divides the rod body 21 into a slurry outlet part 211 and a driving part 212. A flange hole 251 is formed in the rod flange 25. An end flange 24 is fixedly installed at the top of the slurry outlet part 211, and a slurry passing hole 22 is arranged in the slurry outlet part. The slurry passing hole 22 penetrates the top end surface of the rod body in vertical direction. A slurry hole 23 is formed in the outer wall of the slurry passing hole, and a short pipe 28 is screwed in the slurry hole 23 in threaded mode.

[0041] The adapter 52 is bolted on the upper flange, so that the rotary joint is connected to the output shaft of the power head through the adapter. The lower flange is detachably connected to the end flange 24 through bolts, so that the rotary joint and the pile connector 20 are connected together, and the liquid outlet of the rotary joint is connected to the slurry passing hole 22.

[0042] In the embodiment, the driving part 212 has an outer periphery surface with the same shape as the inner periphery surface of the driving hole 121. The driving part 212 is inserted into the driving hole, the flange hole 251 of the rod flange is sleeved on the connecting bolt 14, and the connecting nut 141 is screwed on the connecting bolt, so that the pile connector 20 is detachably fixed on the pile head of the special-shaped tubular pile. The driving part can drive the special-shaped tubular pile to rotate. A pipe passing hole 252 is arranged on the rod flange, and the pipe passing hole is opposite to the slurry pipe hole 171 in up-down direction when the rod flange is connected to the pile.

[0043] An internal thread is arranged on the end of the slurry pipe located on the pile head. The short pipe 29 is screwed on the internal thread after passing through the pipe passing hole and the slurry pipe hole in sequence. The short pipe 28 is connected to the short pipe 29 through a joint 281, so that the slurry passing hole 22 is connected to the slurry pipe. Therefore, the liquid outlet of the rotary joint is connected to the slurry pipe through the slurry passing hole 22. The short pipe 28, the short pipe 29 and the joint 281 jointly constitute an external pipe. In operation, the slurry inlet pipe 322 is connected to the cement slurry pipe 53 of the grouting device, so that the liquid inlet of the rotary joint is connected to the grouting device.

[0044] The construction steps of the cement-soil mixing pile in the construction system in the embodiment are described as follows, which specifically include the following steps.

[0045] (1) The output shaft of the power head 51 of the rotary pile machine 90 is connected to the upper flange 372 of the rotary joint through the adapter 52, and the lower flange 371 of the rotary joint is connected to the end flange. The special-shaped tubular pile 10 is hoisted to be approximately vertical, then the driving part 212 of the pile body connector 20 is inserted into the driving hole 121, the connecting bolt 14 is passed through the flange hole 251 of the flange of the rod body, and the connecting nut 141 is screwed on the connecting bolt, so that the pile body connector 20 is detachably fixed on the pile head of the special-shaped tubular pile. The connection of the cement slurry pipeline is completed by connecting the short pipe 28 to the short connecting pipe 29 through the socket 281, and connecting the slurry inlet pipe 322 to the cement slurry pipeline 53 of the grouting device. The short pipe 28 and the short connecting pipe 29 are respectively screwed on the slurry hole 23 and the grouting pipe in advance.

[0046] (2) The power head 51 of the rotary pile machine is started, the special-shaped tubular pile is rotated and sunk at a set position, and the cement slurry is introduced into the grouting pipe through the rotary joint, and the cement slurry is sprayed outwards through the grouting hole and mixed with the underground soil to form cement soil. The grouting pressure of the cement slurry is 4 MPa.

[0047] (3) When the special-shaped tubular pile is sunk to a set depth, the pile body connector 20 is detached from the special-shaped tubular pile which has completed sinking, and the construction of the cement soil mixing and reinforced composite pile is completed.

[0048] The formed cement soil mixing and reinforced composite pile includes the special-shaped tubular pile and the cement soil mixing pile wrapped around the special-shaped tubular pile, the cement soil mixing pile plays a reinforcing effect, improves the pile end resistance and the pile side friction, and can effectively improve the pile foundation bearing capacity, especially the compressive bearing capacity, can shorten the length of the pile foundation, and effectively improve the economy of the project.

[0049] By using the application, not only the solidification contact area of the pile body and the cement soil layer is increased, but also the stirring blade located at the lower end of the pile body can greatly improve the vertical compression resistance and uplift capacity of the pile foundation.

[0050] In addition, since the construction of the cement soil mixing pile and the rotary sinking of the special-shaped tubular pile are carried out at the same time, the construction efficiency is improved, and the height of the cement soil mixing pile and the special-shaped tubular pile is guaranteed to be concentric. Compared with the reinforced composite pile formed by the conventional post-insertion method of the prestressed concrete tubular pile, there is no harm caused by the soil squeezing effect.

Claims

1. A construction system of a cement-soil mixing and reinforced composite pile, characterized by, The utility model relates to a rotary joint, a pile body connector and a special-shaped pipe pile which are detachably connected in sequence, and the rotary joint is used for being connected to a power head of a rotary pile machine. The special-shaped pipe pile comprises a circular pile body, opposite ends of the pile body are formed into a pile head and a pile end respectively, the pile head faces upward, and the pile end faces downward; a driving hole is arranged in the pile body, the driving hole penetrates the end face of the pile head in the vertical direction, the driving hole is a regular polygon, and the driving hole is coaxially arranged with the pile body; a connecting bolt and a grouting pipe are embedded in the pile body, the connecting bolt extends out of the end face of the pile head in the vertical direction, a grouting hole is arranged at the pile end, one end of the grouting pipe penetrates the upper end face of the pile head upward, and the other end of the grouting pipe is communicated with the grouting hole; a stirring blade is further arranged at the pile end; the special-shaped pipe pile is a prestressed pipe pile. The rotary joint has a liquid inlet and a liquid outlet which are communicated with each other, the liquid inlet is used for being communicated with a grouting device, and the liquid outlet is detachably communicated with the grouting pipe.

2. The construction system of claim 1, wherein, The pile body has a central hole which extends in the vertical direction and is communicated with the driving hole, and one end of the central hole which faces the pile end is a closed end.

3. The construction system of claim 2, wherein, The central hole is circular.

4. The construction system of claim 1, wherein, The rotary joint comprises an inner pipe and an outer pipe which are coaxially sleeved together, the inner pipe and the outer pipe both extend in the vertical direction, the two ends of the outer pipe are rotatably connected to the inner pipe through bearings, an annular cavity is formed between the inner pipe and the outer pipe, the inner pipe has a liquid inlet hole which is communicated with the annular cavity and the inner cavity of the inner pipe, and the outer pipe has a liquid inlet which is communicated with the annular cavity; A connecting lug is arranged on the outer pipe, the connecting lug is fixedly connected to a fixed component of the rotary pile machine; one end of the inner pipe is detachably connected to an output shaft of the power head, the other end of the inner pipe is connected to the pile body connector through bolts, and one end of the inner cavity of the inner pipe which faces the pile body connector is formed into a liquid outlet.

5. The construction system of claim 4, wherein, An upper sealing ring and a lower sealing ring are arranged in the annular cavity, the upper sealing ring is located on the upper side of the lower sealing ring, the upper sealing ring is used for sealing the upper end of the annular cavity, and the lower sealing ring is used for sealing the lower end of the annular cavity; in the vertical direction, the liquid inlet hole and the liquid inlet are located between the upper sealing ring and the lower sealing ring.

6. The construction system of claim 4, wherein, The pile body connector comprises a rod body and a rod body flange, the rod body extends in the vertical direction, the rod body flange is fixedly arranged at the middle part of the rod body, the rod body flange divides the rod body into a grouting outlet part and a driving part, the grouting outlet part is located on the upper side of the driving part, an end flange is fixedly arranged at the top end of the grouting outlet part, a grouting hole is arranged in the grouting outlet part and penetrates the top end face of the rod body in the vertical direction, the liquid outlet of the rotary joint is communicated with the grouting pipe through the grouting hole, and the pile body connector is connected to the rotary joint through the end flange. The driving part has an outer periphery which is the same as the shape of the inner periphery of the driving hole, the pile body connector is arranged on the pile head of the special-shaped pipe pile through the rod body flange, the driving part is inserted into the driving hole, and the special-shaped pipe pile can be rotated under the driving of the driving part.

7. The construction system of claim 6, wherein, A grout hole which is communicated with the grouting hole is arranged on the outer wall of the grouting hole, a pipe penetrating hole is arranged on the rod body flange, one end of an external connecting pipe is communicated with the grout hole, and the other end of the external connecting pipe penetrates the pipe penetrating hole and is connected to the grouting pipe.

8. The construction system of claim 4, wherein, The connecting lug is detachably connected to the shell of the power head.

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