Manufacturing mold and manufacturing method of expansion material block

Abstract

The invention relates to a manufacturing mold and a manufacturing method for pressing a powder material into an expansion material block for improving the bearing capacity of a pile end. Manufacturing a barrel side wall of the barrel-shaped supporting device with the same inner cross section size and height as the expansion material block; the lower section hole of the manufactured mold is as high as the cylinder side wall, the inner circumference cross section size is the same as the outer circumference cross section of the cylinder side wall, the upper section hole is the same as the inner circumference cross section of the cylinder side wall, and the upper section hole and the lower section hole are concentric; mounting the cylinder side wall in a lower section hole of the mold; the device is placed on a pressure-bearing table of a press machine, expansion material powder is filled into an appropriate height of an upper section hole formed by combining a mold and a barrel side wall, a mandrel is placed in, pressure forming, pressure relief and demolding are carried out, and a combination formed by an expansion material block and the barrel side wall tightly hooped on the side wall of the expansion material block is obtained; the invention aims to improve the manufacturing efficiency of the expansion material block, increase the yield and improve the utilization efficiency of the expansion material block.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation treatment and pile foundation engineering construction, and particularly relates to a mold and a method for making a swelling material block for improving the bearing capacity of a pile end by pressing a powder material. Background Art

[0002] Patent applications CN117822545A and CN202311805587.9 propose expansion devices for improving the bearing capacity of pile ends and their design and preparation methods. The expansion device uses a sufficiently high pressure to press the material powder that can produce expansion into an expansion material block with a certain shape and a sufficiently high density, and then loads the expansion material block into a cylindrical support device, and then installs the expansion device consisting of the expansion material block and the cylindrical support device and other components at the bottom end of the pile.

[0003] The pressing method of the expansion material block mainly includes: filling the expansion material powder in a mold, and then pressing and molding with a sufficiently high pressure; usually it is necessary to leave it for a period of time, and the mold can only be removed after the internal pressure generated in the expansion material block due to the pressure molding is balanced or dissipated; otherwise, if the mold is removed immediately after the pressure molding, the expansion material block may be cracked due to the internal pressure after the mold is removed. Even if the expansion material block is not cracked, the internal pressure will cause the volume of the expansion material block to increase, making it difficult to load the expansion material block into the cylindrical support device; or in order to adapt to the volume change of the volume increment generated by the expansion material block, the tolerance matching surplus between the expansion material block and the cylindrical support device must be increased, and part of the expansion of the expansion material block will have to be used to fill the gap caused by the excessive tolerance matching surplus, which will inevitably lead to a reduction in the effective expansion of the expansion material block. In addition, in the process from the expansion material block being pressed and molded to the expansion material block being loaded into the cylindrical support device, the handling and installation processes are very likely to cause the expansion material block to break, resulting in a decrease in the yield rate. The above problems will inevitably lead to a decrease in the manufacturing efficiency of the expansion device and an increase in the cost. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned method for making an expansion material block, the present invention provides a mold and a method for making an expansion material block.

[0005] The manufacturing mold and manufacturing method of the expansion material block described in the present invention are realized by the following steps:

[0006] S1. Manufacturing a cylindrical side wall of the cylindrical support device, wherein the height of the cylindrical side wall is equal to the height of the expansion material block, and the shape and size of the inner circumferential cross section of the cylindrical side wall are the same as the shape and size of the cross section of the expansion material block;

[0007] S2. Make a mold, the mold mainly includes a lower section and an upper section, the height of the mold is greater than the height of the expansion material block, within the range where the lower section of the mold is equal to the height of the barrel side wall, there is a lower section hole whose inner cross section is equal to the shape and size of the outer cross section of the barrel side wall; the upper section of the mold has an upper section hole that is the same shape and concentric with the lower section hole and whose inner cross section size is equal to the cross section size of the expansion material block;

[0008] S3, installing the side wall of the tube into the lower hole of the mold;

[0009] S4. Place the device described in S3 on the pressure platform of the press machine, and fill the expanded material powder into the hole of the device described in S3 to an appropriate height according to the design required pressure, the density of the expanded material block and the bulk density of the expanded material powder. Optionally, a core shaft with the same cross-section as the expanded material block and a length not less than the height of the upper hole can be placed in the hole to guide and pressurize the expanded material powder when compacting the expanded material powder. Then, apply the design required pressure on the core shaft to compact the expanded material powder to the design required height and density of the expanded material block.

[0010] S5, taking out the combination of the expansion material block and the side wall of the tube tightly clamped on the side wall from the mold, thus completing the production of the expansion material block.

[0011] The mold for making the expansion material block is mainly composed of a complete cylindrical mold, so that the combination of the completed expansion material block and the side wall of the cylinder tightly clamped on the side wall can be axially demoulded.

[0012] Preferably, in order to facilitate demolding, the mold can be divided into two semi-cylindrical parts, and the two semi-cylindrical parts of the mold 1 are assembled around the cylinder side wall 4. The assembly adopts a known method (such as bolts, buckles, etc.) to combine the two semi-cylindrical parts into a complete cylinder and make its inner wall tightly against the cylinder side wall.

[0013] Preferably, in order to avoid the situation in which the mold is displaced upward due to the pressure applied during the manufacturing process of the expandable material block, which may cause the expandable material powder to be extruded laterally along the bottom end surface of the mold and thereby cause the size of the expandable material block to deviate from the design value, a buckle can be welded to the lower end of the outer side of the cylinder wall of the mold, so that the mold can be tightly fixed on a base matching the buckle of the mold, or side ears can be welded to the bottom of the lower end of the mold, and bolts or other known fixing methods can be provided on the side ears, so that the mold can be fixed on a base, thereby limiting the upward displacement of the mold during the manufacturing process of the expandable material block.

[0014] The mold and the side wall of the cylinder are made of materials with sufficient strength and rigidity (such as steel, etc.). The thickness of the mold is determined according to the pressure level that the mold needs to withstand and the deformation limit under the pressure; the thickness of the side wall of the cylinder is determined according to the pressure level that the mold needs to withstand during the production of the expansion material block and the deformation limit under the pressure, as well as the load it is subjected to during the process of being implanted into the ground with the pile and the deformation limit under the load; the shape and size of the cross-section of the combination of the expansion material block and the side wall of the cylinder are determined according to the shape and size of the outer side of the cross-section of the pile.

[0015] Preferably, the above-mentioned preferred modes of the molds can be combined.

[0016] The advantages of the present invention are as follows:

[0017] When using the existing technology to make expansion material blocks, after pressure molding, it is usually necessary to leave it aside for a period of time, and the mold can only be removed after the internal pressure generated in the expansion material block due to pressure molding is balanced or dissipated, so as to prevent the expansion material block from cracking or even disintegrating under the action of internal stress. Therefore, the efficiency of making expansion material blocks using the existing technology is not high, and the yield rate is not high. When using the method of the present invention to make expansion material blocks, it is possible to avoid the damage caused by internal stress when removing the mold after pressurizing the expansion material block, thereby reducing the waiting time, improving the production efficiency, and improving the yield rate.

[0018] When using the prior art to make an expansion material block, after pressure forming, the expansion material block often expands due to the internal pressure after demolding; since the expansion amount is difficult to accurately control, the tolerance between the expansion material block and the side wall of the cylinder is difficult to control, or the expansion material block cannot be put in, or part of the expansion of the expansion material block has to be used to fill the gap caused by the excessive tolerance, which inevitably leads to a reduction in the effective expansion amount of the expansion material block. The present invention can avoid the phenomenon of difficult control of the tolerance between the side wall of the cylinder and the expansion material block and the adverse consequences caused by it.

[0019] In the existing technology for making expansion material blocks, the expansion material blocks are pressed and placed in the side wall of the cylinder in two steps. During the process from the expansion material blocks being pressed and formed to the side wall of the cylinder, the expansion material blocks are easily broken due to the handling and installation process, resulting in a decrease in the yield rate. The present invention combines these two steps into one step, further improving the production efficiency of the expansion material blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of mold structure

[0021] Figure 2 Schematic diagram of loading expansion material powder

[0022] Figure 3 Schematic diagram of making a block of expanded material and pressurizing it

[0023] Figure 4 Schematic diagram of the separation of the expansion material block and the cylinder side wall combination from the mold

[0024] Figure 5 Schematic diagram of the combination of expansion material block and cylinder side wall

[0025] Figure 6 Schematic diagram of the cross-sectional structure of two semi-cylindrical molds combined with bolts

[0026] Figure 7 The mold is fixed to the base structure with bolts

[0027] Figure 8 Schematic diagram of the cross-section structure of a pile with expansion material blocks

[0028] in, Figure 1-Figure 8 middle:

[0029] 1. Mould; 11. Lower hole; 12. Upper hole; 13. Bolt; 14. Fixing seat; 2. Mandrel; 3. Expansion material block; 4. Side wall of cylinder; 5. Base; 6. Prefabricated pipe pile; 7. Upper end plate; 8. Lower end plate; 9. Conical rib plate. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0031] The present invention will be described in detail below with reference to the accompanying drawings.

[0032] (1) Mold 1 adopts Figure 1 The main structure shown is a complete cylindrical structure assembly, which is directly placed on the pressure platform of the press; or Figure 6 The mold 1 shown in the figure uses bolts 13 to form a mold structure with two semi-cylindrical parts, and the bolts 13 can be removed to demould; or Figure 7 In the manner shown, a fixing seat 14 is provided at the lower end of the lower section of the mold 1, and the fixing seat 14 of the mold 1 is fixed to the base 5 by bolts 13; or Figure 6 and Figure 7 The combined mold of the structure shown, the mold 1 is composed of two semi-cylindrical parts combined into a complete mold structure, and a fixing seat 14 is set at the lower end of the lower section of the mold 1; the cylinder side wall 4 is installed in the lower section hole 11 of any form of the mold 1 described above, and the device combining the above-mentioned mold 1 and the cylinder side wall 4 is placed on the pressure platform of the press.

[0033] (2) According to the design pressure, the design density of the expansion material block 3 and the bulk density of the expansion material powder, the expansion material powder is loaded into the hole of the device (1) to an appropriate height, such as Figure 2 As shown, the mandrel 2 is placed on the expanded material powder, as shown in FIG. Figure 3 Apply the required pressure on the mandrel 2 to compact the expanded material powder to the required height and density of the expanded material block 3; Figure 4 As shown in FIG. 1 , the expansion material block 3 and the barrel side wall 4 are separated from the mold 1, and the production of the expansion material block 3 is completed (see FIG. Figure 5 ).

[0034] (3) At the upper and lower ends of the combination of the expansion material block 3 and the barrel side wall 4, the connection method (including but not limited to welding, bolt connection, magnetic attraction, gluing, etc.) of the support tube and the upper end plate and the lower end plate in the load-bearing device described in patent applications CN117822545A and CN202311805587.9 can be adopted to connect the upper end plate and the lower end plate to the combination of the expansion material block 3 and the barrel side wall 4 respectively; in the connection between the upper end plate and the barrel side wall 4 or the connection between the lower end plate and the barrel side wall 4, the connection strength of at least one end is lower than the expansion stress generated by the expansion material block 3 to ensure that the connection fails when the expansion material block 3 expands.

[0035] (4) The connection method between the load-bearing device and the bottom end of the pile described in patent applications CN117822545A and CN202311805587.9 (including but not limited to welding or bonding methods) can be adopted to connect the upper end plate of the combination of the expansion material block 3 and the barrel side wall 4 installed with the upper end plate and the lower end plate to the bottom end surface of the pile. If the bottom end surface of the pile is a complete plane, the upper end surface of the combination of the expansion material block 3 and the barrel side wall 4 can be directly connected to the bottom surface of the pile without adding an end plate, and the upper end surface of the barrel side wall 4 tightly clamped to the side wall of the expansion material block 3 is directly connected to the bottom surface of the pile.

[0036] The pile with the expansion material block 3 and the tube side wall 4 installed at the bottom of the pile is implanted into the ground, and the construction of the high-bearing capacity pile with the expansion material block installed at the bottom of the pile is completed. Figure 6 shown.

[0037] Embodiment 1

[0038] Combine the following Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 8The invention is further described. The engineering geological conditions are as follows: 0-7m is clay, soft plastic, partially plastic, and lateral friction resistance is 10kPa; 14-18m is silty clay, soft plastic, and lateral friction resistance is 20kPa; 18-40m is clayey silt, dense, lateral friction resistance is 30kPa, and the characteristic value of soil end resistance at the pile end is 1500kPa. The standard value of the vertical ultimate bearing capacity of a single pile of PHC-AB600 (110) prefabricated pipe piles designed for a certain construction project is 3000kN, with a diameter of 600mm and a pile length of 25m. An expansion material device is installed at the bottom of the prefabricated pipe pile.

[0039] The diameter of the combined body of the expansion material block 3 and the cylinder side wall 4 is 600mm and the height is 300mm. The cylinder side wall 4 is made of steel plate with a wall thickness of 5mm; there are thin slits with a width of 0.1mm and a length of 12cm cut thereon, with a circumferential spacing of 1cm, and water-permeable holes with a spacing of 2cm between the upper and lower rows of thin slits. The mold 1 used is made of gray cast iron, and the mold 1 is 1000mm high. The lower hole 11 has a wall thickness of 40mm, a height of 300mm, and an inner diameter of 600mm, and the upper hole 12 has a wall thickness of 45mm, a height of 700mm, and an inner diameter of 580mm.

[0040] Mold 1 adopts Figure 6 The structure shown is mainly composed of two semi-cylindrical parts, which are integrated with bolts 13; the cylinder side wall 4 is placed in the lower hole 11 of the mold 1, and the mold 1 is integrated with bolts 13 so that the inner wall of the mold 1 is closely attached to the cylinder side wall 4, and is placed on a pressure platform; the expansion material powder is loaded into the combination of the mold 1 and the cylinder side wall 4, and the mandrel 2 is placed. The mandrel 2 is made of alloy steel, and the pressure surface is consistent with the shape and size of the expansion material block 3, as shown in FIG. Figure 2 As shown, a press is used to press the expansion material powder to a height of 300 mm, and the density of the expansion material block 3 is not less than 2500 kg / m3. Figure 3 Slowly release the pressure, remove the mandrel 2, remove the bolts 13 on the mold 1 for demoulding, disassemble the two semi-cylindrical structures of the mold 1, and obtain the following Figure 5 The expansion material block 3 shown is combined with the side wall 4 of the cylinder.

[0041] The upper end of the expansion material block 3 and the cylinder side wall 4 combination is connected to the upper end plate 7 and the expansion material block 3 and the cylinder side wall 4 combination by welding, and the lower end is connected to the lower end plate 8 and the expansion material block 3 and the cylinder side wall 4 combination by magnetic attraction; the upper end surface of the upper end plate 7 of the expansion material block 3 and the cylinder side wall 4 combination installed with the upper end plate 7 and the lower end plate 8 is welded to the iron plate of the bottom end surface of the pile, and the lower end surface of the lower end plate 8 is fixedly provided with a conical rib plate 9, which is implanted with the prefabricated pipe pile 6 at the position with the designed pile length of 25m, that is, the construction of the high-bearing capacity pile with the expansion material block installed at the bottom end of the pile is completed, such as Figure 8 As shown, water penetrates into the expansion material block 3 along the water-permeable holes on the side wall 4 of the cylinder, and the expansion material block 3 absorbs water and expands.

[0042] The present invention is not limited to the above-mentioned embodiments. Regardless of any changes in shape or material composition, any design using the structure and method provided by the present invention is a variation of the present invention and should be considered to be within the scope of protection of the present invention.

Claims

1. A method for making an expansion material block, characterized in that: S1, manufacturing a cylindrical side wall (4) of the cylindrical support device, wherein the height of the cylindrical side wall (4) is equal to the height of the expansion material block (3), and the shape and size of the inner circumferential cross section of the cylindrical side wall (4) are the same as the shape and size of the cross section of the expansion material block (3); S2, manufacturing a mold (1), wherein the mold (1) mainly comprises a lower section and an upper section, wherein the height of the mold (1) is greater than the height of the expansion material block (3), and within a range where the lower section of the mold (1) is equal in height to the cylinder side wall (4), there is a lower section hole (11) whose inner cross section is equal in shape and size to the outer cross section of the cylinder side wall (4); and the upper section of the mold (1) has an upper section hole (12) whose shape is the same as and concentric with the lower section hole (11) and whose inner cross section is equal in size to the cross section of the expansion material block (3); S3, installing the barrel side wall (4) in the lower hole (11) of the mold (1); S4, placing the device described in S3 on the pressure table of the press, and filling the expanded material powder into the hole of the device described in S3 to an appropriate height according to the pressure required by the design, the density of the expanded material block (3) and the bulk density of the expanded material powder. A core shaft (2) having the same cross section as the expanded material block (3) and a length not less than the height of the upper hole can be selectively placed in the upper hole (12) of the mold (1) to guide and pressurize the expanded material powder when compacting the expanded material powder, and then applying the pressure required by the design to the core shaft (2) to compact the expanded material powder to the height and density of the expanded material block (3) required by the design; S5, taking out the combination of the expansion material block (3) and the tube side wall (4) tightly clamped to the side wall from the mold (1), thus completing the production of the expansion material block.

2. A mold and method for making an expansion material block according to claim 1, characterized in that: The mold for making the expansion material block is mainly a complete cylindrical mold (1), so that the combination of the expansion material block (3) and the cylindrical side wall (4) tightly bound to the side wall can be axially demoulded; or it is mainly composed of two semi-cylindrical parts that can be combined into a mold (1), and after the combination of the expansion material block (3) and the cylindrical side wall (4) tightly bound to the side wall is completed, the mold (1) can be disassembled and demoulded.

3. A mold and method for making an expansion material block according to claims 1 to 2, characterized in that: The mold (1) can be directly placed on the pressure plate of a press to produce an expansion material block; or a known detachable fixing method can be used between the lower end of the cylinder wall of the mold (1) and the base (5) to prevent the mold (1) from shifting upward during the process of preparing the expansion material block.

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