Pile head static splitting directional forcible entry device and method

Abstract

The invention relates to the technical field of concrete pile head forcible entry, and provides a pile head static splitting directional forcible entry device and a forcible entry method.The forcible entry device is arranged in a concrete pile head and comprises a forcible entry pipe, and a containing cavity used for containing a crushing agent and a heating piece is formed in the forcible entry pipe; a directional hole is formed in the side wall of the forcible entry pipe in the length direction of the forcible entry pipe in a penetrating mode, pipe plugs are detachably arranged at the two ends of the forcible entry pipe and used for plugging the two ends of the forcible entry pipe, heating pieces are arranged on the pipe plugs, and the crushing agent can wrap the parts, located in the containing cavity, of the heating pieces. The crushing efficiency of the static crushing agent applied to pile head crushing can be improved, multi-point synchronous crushing can be achieved, meanwhile, directional crushing can be achieved, and the pile head crushing quality is improved.

Description

Technical Field

[0001] This invention relates to the field of concrete pile head demolition technology, specifically to a static splitting and directional demolition device and method for pile heads. Background Technology

[0002] Cast-in-place piles are widely used in various civil engineering fields. After the cast-in-place piles are formed, the pile heads need to be broken. At present, the most common method of pile head breaking is still manual hand-held pneumatic hammer breaking. For large-diameter pile heads (currently the largest cast-in-place pile diameter is greater than 5 meters), there are problems such as high labor intensity for workers, high construction noise, and a lot of dust. It is not suitable for the demolition of concrete pile heads in densely populated urban areas, important traffic arteries, and around special equipment.

[0003] There is also traditional blasting technology, which involves placing explosives into a device to cause the concrete structure to be rapidly destroyed under the action of the blast wave. Although this type of blasting method has the advantages of low cost, wide applicability and high power, traditional explosive blasting has disadvantages such as the danger of misfires and strict control.

[0004] Alternatively, static crushing technology can be used. Static crushing technology involves mixing a crushing agent into a slurry and injecting it into the boreholes of the structure. During the hydration reaction of the crushing agent, its volume expands and generates radial expansion pressure. Due to the low tensile strength of brittle materials such as concrete, cracks are generated and gradually develop until the structure breaks.

[0005] Static fracturing differs from traditional blasting. Static fracturing agents utilize the reaction of calcium oxide with water to generate calcium hydroxide, releasing heat. During this process, the static fracturing agent expands 2-4 times in volume, generating an expansion force of 30-100 MPa, exceeding the tensile strength of most concrete, thus easily fracturing the concrete. Furthermore, static fracturing agents are simple and inexpensive, with low requirements for use and control, showing good prospects for widespread application. However, static fracturing technology also has disadvantages such as long rock-breaking time, weaker explosive power, environmental pollution from reaction products, and poor performance at low temperatures.

[0006] Thermite is a material made by mixing aluminum powder with metal oxides. Under external energy stimulation, it undergoes a vigorous redox reaction, releasing heat energy, making it a common energetic material. Thermite reactions are characterized by high exothermicity and self-sustaining combustion. Its reactants are inexpensive and the products are of high purity, making it commonly used in the preparation of metal compounds, welding of pipes and rails, and internal corrosion protection of pipes. Static fracturing agents are greatly affected by temperature and have a long action time, resulting in a limited range of applications. Thermite, as a self-propagating material, has a theoretical combustion temperature of not less than 1800K. This means that thermite that meets the self-sustaining combustion requirement can heat static fracturing agents. Furthermore, the self-sustaining combustion phenomenon of thermite allows it to serve as a heating material throughout the static fracturing process, enhancing the effectiveness of static blasting. In addition, when using static fracturing agents to break pile heads, it is necessary to control the development of internal cracks in the pile head, determine the boundaries of static splitting, and ensure that pile head breaking is confined to a fixed elevation range. Therefore, directional breaking methods are required.

[0007] Traditional static fracturing technology involves creating axially arranged quincunx-shaped holes on the pile head, filling the holes with static fracturing agent, and waiting 6 to 48 hours or even more to complete the fracturing of a single pile head. Furthermore, the fracturing quality is difficult to control, and the expanding cracks may extend downwards and exceed the predetermined height of the cast-in-place pile, causing cracks in the pile and significantly affecting its integrity and safety. The construction quality and efficiency need to be further improved.

[0008] Therefore, in order to address the above problems, a static splitting and directional demolition device and method for pile heads is proposed to solve these problems. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention develops a static splitting and directional breaking device and method for pile heads. This invention can improve the breaking efficiency when static fracturing agents are applied to pile head breaking, and can achieve multi-point synchronous breaking, while also achieving directional breaking, thereby improving the quality of pile head breaking.

[0010] To achieve the above objectives, the present invention employs the following technical solution: A static splitting and directional breaking device for pile heads is installed inside a concrete pile head. It includes a breaking tube with a cavity for accommodating a breaking agent and a heating element inside the breaking tube. A directional hole is opened through the side wall of the breaking tube along its length. Pipe plugs are detachably installed at both ends of the breaking tube to seal both ends of the breaking tube. A heating element is installed on the pipe plugs, and the breaking agent can cover the portion of the heating element located in the cavity.

[0011] Preferably, the demolition tube is made of plastic and has a diameter of 26-38 mm. The length of the demolition tube is determined according to the depth of the corresponding demolition hole drilled on the concrete pile head. The demolition tube is rotated and set inside the demolition hole of the concrete pile head to adjust the direction of the directional hole, and the axis of the demolition tube is perpendicular to the axis of the concrete pile head.

[0012] Preferably, the breaking agent is a mixture of calcium oxide and water, which can completely fill the containment cavity, and the static breaking agent can flow out from the directional hole.

[0013] Preferably, the axis of the directional hole is perpendicular to the axis of the breaking tube, and several directional holes are evenly arranged along the length of the breaking tube, with the axes of the directional holes all located in the same plane.

[0014] Preferably, a covering strip is provided on the directional hole, which is used to temporarily cover the directional hole before the breaking tube is inserted into the breaking hole.

[0015] Preferably, the pipe plug is made of rubber and includes a sealing section and an outer sealing section. The outer side of the sealing section has multiple circumferential sealing bands arranged axially, and the diameter of the sealing bands is larger than the inner diameter of the corresponding broken pipe. The end of the sealing section away from the outer sealing section is set as a frustum-shaped insertion end. The diameter of the outer sealing section is not less than the inner diameter of the corresponding broken pipe. The outer side of the outer sealing section is provided with friction grooves to increase friction. The middle of the pipe plug is used for the passage of the heating element and can support the heating element.

[0016] Preferably, the heating element includes a heating tube with a diameter smaller than that of the breaking tube. The heating tube contains a thermite, and one end of the heating tube is provided with a conical plug. The conical plug is conical in shape and can penetrate the tube plug, allowing the tube plug to support the heating tube. The other end of the heating tube is connected to the output end of a fiber laser, which is used to ignite the thermite inside the heating tube.

[0017] Preferably, the heating tube is a graphite tube, and a baffle is set along the length of the inner cavity of the graphite tube. The length of the baffle is the same as the length of the heating tube, and the width of the baffle is the same as the inner diameter of the graphite tube, so as to divide the inner cavity of the graphite tube into a left cavity and a right cavity, and the thermite fills the left cavity or the right cavity.

[0018] The present invention also provides a method for static splitting and directional demolition of pile heads, including the above-mentioned static splitting and directional demolition device for pile heads, and further including the following steps: Step 1: Drilling. After the pile head is exposed, lay out the circumferential positioning line 5-10 cm above the predetermined height of the cast-in-place pile. Use a 3D laser scanner to locate the distribution of the reinforcing bars in the steel cage, avoiding the positions of the reinforcing bars. Then, drill evenly distributed demolition holes along the radial direction of the pile head in the circumferential direction of the laid-out line. Then, use a high-pressure air duct to clean the demolition holes. The diameter of the demolition holes is 28-40 mm, and the length of the demolition holes is [missing information - likely a percentage] of the pile head diameter. ~ The holes are not connected to each other to avoid interference between the breaking pipes; Step 2: Prepare the slurry. Prepare the fracturing agent slurry with a weight ratio of calcium oxide to water of 3:1, and stir until it becomes a uniform paste. Step 3: Prepare the powder mixture. Mix the aluminum powder with the powdered metal oxides evenly. The metal oxides can be selected from among iron(III) oxide, iron(II) oxide, and copper oxide. Step 4: Tube making. Cut the demolition tube according to the depth of the demolition hole, so that the length of the demolition tube is 2-3 cm shorter than the depth of the corresponding demolition hole. Completely immerse the cut demolition tube into the slurry, so that the cavity of the demolition tube is filled with the demolition agent slurry. Then, seal both ends of the demolition tube in the slurry with a tube plug to prevent the slurry from spilling out when the demolition tube is moved. Step 5: Filling with powder. Cut the heating tube according to the depth of the drilled hole, so that the length of the heating tube is 3-5 cm longer than the depth of the corresponding drilled hole. Place the conical plug at one end of the heating tube, and then insert a baffle of the same length as the heating tube into the heating tube. Then fill the left or right cavity of the baffle with thermite powder through the funnel. Finally, seal the heating tube with another conical plug to prevent the powder from spilling out. Step Six: Filling the Hole. Remove the broken tube from the slurry and fill it into the corresponding broken hole. During the movement of the broken tube, keep the directional hole facing upward to prevent the slurry from spilling out. Remove the hole cover strip when inserting the broken tube into the broken hole. After the broken tube is inserted, it can be slightly rotated to adjust the orientation of the directional hole, but the rotation angle should not exceed 90°. Then, fully insert the broken tube into the broken hole. Next, take out the heating tube corresponding to the broken hole. Insert the conical plug at one end of the heating tube and pass through the plug on the outside of the broken tube. Then continue to insert it inward until the conical plug on the inside of the broken hole is inserted into the plug on the other end to limit the heating tube. When the heating tube is inserted into the broken tube, it occupies the space of the broken tube's receiving cavity to squeeze the slurry in the receiving cavity out of the directional hole, so that the slurry flows into the gap between the outer wall of the broken tube and the broken hole. Step 7: Demolition. Fill all the demolition holes, then set up a circumferential restraint strap around the outside of the demolition holes to prevent the contents from being ejected. Then remove the conical plugs from the outer ends of all the heating tubes and connect the end to the output end of the fiber laser so that the laser can ignite the thermite powder. After connecting all the heating tubes to the fiber laser, the workers retreat to a safe distance, the laser is ignited, and the simultaneous and rapid demolition of multiple demolition holes is completed. Step 8: Cleaning. Spray the broken pile head fragments with an alkaline sodium carbonate solution to neutralize the residue from the crushing reaction, then clean up the pile head fragments. For the small amount of pile head remaining above the predetermined height of the cast-in-place pile, use other methods such as water jet cutting and handheld cutting machines for precise removal and clean up the waste, thus completing the removal of the pile head.

[0019] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. The above technical solution has the following advantages: This invention incorporates a breaking tube that can store static fracturing agent, facilitating the rapid filling of the static fracturing agent into the radially opened breaking holes on the pile head, while preventing the static fracturing agent from flowing out of the breaking holes, thus ensuring the quality of the fracturing agent filling. By setting directional holes on the breaking pipe, and the direction of the directional holes can be freely adjusted, the pile body can be broken in a directional manner in conjunction with the induction groove of the breaking hole, so as to avoid the cracks extending downwards beyond the predetermined height of the cast-in-place pile and thus reduce the quality of the cast-in-place pile, thereby improving the quality of breaking. By setting up a heating element, the heating element can heat the expansion reaction of the static fracturing agent to accelerate the expansion rate of the fracturing agent, thereby improving the efficiency of pile head fracturing. The time can be reduced from several hours to less than one hour, which greatly improves the efficiency of construction. By first inserting the demolition tube into the demolition hole, and then inserting the heating tube into the demolition tube, the demolition agent inside the demolition tube can flow out from the directional hole after being squeezed, so as to fill the gap between the outer wall of the demolition tube and the inner wall of the directional hole, thereby further improving the quality and efficiency of demolition. By setting pipe plugs to seal both ends of the breaking pipe, the breaking agent is prevented from flowing out. The pipe plugs are made of rubber, which can be easily penetrated, facilitating the insertion of the heating pipe and improving the practicality of the device. By installing baffles inside the heating tube, uneven distribution of the thermite is avoided, thus improving the quality of the thermite reaction and consequently enhancing the heating effect. By installing restraint straps on the outside of the breaching hole, the danger to workers caused by the expansion of the fracturing agent is prevented from being punctured, thus improving the safety of the construction. By connecting the outer end of the heating tube to the output end of the fiber laser, the thermite can be ignited by the laser, enabling simultaneous and synchronous ignition at multiple locations, thus achieving synchronous crushing. This improves the quality and efficiency of pile head crushing and also enhances construction safety. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0021] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of an embodiment of the present invention. Figure 2 ; Figure 3This is a schematic diagram of the connection structure of the heating element according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the pipe plug structure according to an embodiment of the present invention; Figure 5 This is a side sectional view of the overall structure of an embodiment of the present invention; Figure 6 This is a side sectional view of the heating element according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the overall construction process according to an embodiment of the present invention; Figure 8 for Figure 7 Enlarged view of point A in the middle; Figure 9 This is a schematic diagram of the distribution of breaching holes in an embodiment of the present invention. Figure 1 ; Figure 10 This is a schematic diagram of the distribution of breaching holes in an embodiment of the present invention. Figure 2 .

[0022] In the diagram, 1. Pile head; 2. Demolition pipe; 3. Heating element; 4. Receiving cavity; 5. Directional hole; 6. Pipe plug; 7. Demolition hole; 8. Covering strip; 9. Sealing tape; 10. Insert end; 11. Friction pattern; 12. Heating pipe; 13. Conical plug; 14. Baffle; 15. Reinforcing bar; 16. Restraint band. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 like Figures 1-6 As shown, a static splitting and directional breaking device for a pile head 1 is installed inside a concrete pile head 1. It includes a breaking pipe 2, and a receiving cavity 4 for accommodating a breaking agent and a heating element 3 is provided inside the breaking pipe 2. Several directional holes 5 are opened through the side wall of the breaking pipe 2 along its length. Preferably, gaps are opened between adjacent directional holes 5 to facilitate the expansion and breaking of the breaking pipe 2. Pipe plugs 6 are detachably provided at both ends of the breaking pipe 2 to seal both ends of the breaking pipe 2. A heating element 3 is provided on the pipe plug 6. The heating element 3 is located inside the receiving cavity 4 of the breaking pipe 2 and does not contact the inner wall of the breaking pipe 2. The breaking agent can cover the part of the heating element 3 located inside the receiving cavity 4.

[0025] In this embodiment, the demolition pipe 2 is made of plastic, preferably PVC plastic pipe, which is inexpensive and economical. For concrete pile heads 1 with a diameter of less than three meters, the diameter of the demolition pipe 2 is selected to be between 26 and 38 mm. For concrete pile heads 1 with a diameter of more than three meters, the diameter of the demolition pipe 2 is one seventy-fifth of the diameter of the concrete pile head 1. The length of the demolition pipe 2 is determined according to the depth of the corresponding demolition hole 7 drilled on the concrete pile head 1. The demolition pipe 2 can be rotatably installed in the demolition hole 7 of the concrete pile head 1 to facilitate the adjustment of the direction of the directional hole 5. The axis of the demolition pipe 2 is perpendicular to the axis of the concrete pile head 1, that is, the axis of the demolition pipe 2 is set along the radial direction of the concrete pile head 1.

[0026] In this embodiment, the breaking agent is a slurry of calcium oxide and water in a 3:1 weight ratio. The slurry can completely fill the receiving cavity 4, and the breaking agent can flow out from the directional hole 5, which facilitates filling the gap between the outer wall of the breaking tube 2 and the inner wall of the breaking hole 7. Preferably, the distance between the outer wall of the breaking tube 2 and the inner wall of the breaking hole 7 is less than 1 mm to avoid insufficient filling.

[0027] In this embodiment, the axis of the directional hole 5 is perpendicular to the axis of the breaking tube 2. Several directional holes 5 are evenly arranged along the length of the breaking tube 2, and the axes of the directional holes 5 are all located in the same plane. That is, the directional holes 5 are arranged in a straight line. A gap is opened on the breaking tube 2 between adjacent directional holes 5 to facilitate the breaking tube 2 to burst while preventing the slurry from flowing out easily.

[0028] In this embodiment, a covering strip 8 is provided on the directional hole 5. The covering strip 8 is used to temporarily cover and seal the directional hole 5 before the demolition pipe 2 is inserted into the demolition hole 7 to prevent grout from spilling out. Preferably, the covering strip 8 can be made of rubber strip or tape. It is only necessary to temporarily seal the directional hole 5. The covering strip 8 is removed when one end of the demolition pipe 2 is inserted into the demolition hole 7 to avoid affecting the overflow of grout in the demolition hole 7. This improves the speed at which the construction personnel can move the device and increases the construction efficiency.

[0029] In another embodiment, since the breaking tube 2 is a PVC plastic pipe, a strip of heating wire can be used during the manufacturing process of the breaking tube 2 to heat out a groove that can be easily torn off along the length of the breaking tube 2. The principle is that the high-temperature heating wire cuts the wall of the PVC plastic pipe, but does not completely cut it off, so that the connection thickness between the edge of the groove and the breaking tube 2 is less than 0.2 mm (the wall thickness of a typical PVC plastic pipe is greater than 1 mm), or the edge of the groove and the breaking tube 2 are intermittently connected, so that the construction personnel can manually tear off the groove. When used in construction, the groove has the same function as the hole covering strip 8. The through groove after the groove is torn off is another manifestation of the directional hole 5, which has the same function and is more practical.

[0030] In this embodiment, the pipe plug 6 is made of rubber, preferably butyl rubber, and includes a sealing section and an outer sealing section. The sealing section is used to insert into the broken pipe 2 and seal both ends of the broken pipe 2. The outer sealing section is used to hold or pull out the pipe plug 6. Multiple circumferential sealing bands 9 are arranged axially on the outer side of the sealing section. The diameter of the sealing bands 9 is larger than the inner diameter of the corresponding broken pipe 2, so as to improve the sealing effect of the pipe plug 6 by squeezing and prevent slurry leakage. The end of the sealing section away from the outer sealing section is set as a frustum-shaped insertion end 10. The diameter of the outer sealing section is not less than the inner diameter of the corresponding broken pipe 2, preferably the same as the diameter of the broken hole 7. Friction textures 11 are arranged circumferentially on the outer side of the outer sealing section to increase friction and facilitate handling. The middle part of the pipe plug 6 is used for the heating element 3 to pass through and can support the heating element 3. Preferably, the middle part of the pipe plug 6 has an insertion slit along the length direction to facilitate the rapid insertion of the heating element 3. The insertion slit has almost no thickness to prevent slurry from flowing out.

[0031] In this embodiment, the heating element 3 includes a heating tube 12, the diameter of which is smaller than that of the breaking tube 2. The heating tube 12 is used to hold the thermite. One end of the heating tube 12 is detachably provided with a conical plug 13. The conical plug 13 is conical in shape, which facilitates the insertion of the tube plug 6. The maximum diameter of the conical plug 13 is not greater than the outer diameter of the heating tube 12. The conical plug 13 can penetrate the tube plug 6 and support the heating tube 12. The tube plugs 6 at both ends of the breaking tube 2 cooperate to support the heating tube 12, so that the heating tube 12 does not contact the inner wall of the breaking tube 2. The other end of the heating tube 12 is located outside the breaking tube 2 and is used to connect to the output end of the fiber laser. The fiber laser is used to ignite the thermite inside the heating tube 12.

[0032] In another embodiment, the heating tube 12 is a graphite tube, and a baffle 14 is detachably installed along the length of the inner cavity of the graphite tube. The length of the baffle 14 is the same as or slightly less than the length of the heating tube 12. The baffle 14 is made of plastic plate, and the width of the baffle 14 is the same as the inner diameter of the graphite tube, so as to divide the inner cavity of the graphite tube into a left cavity and a right cavity. The thermite fills the left cavity or the right cavity, so that the thermite is evenly distributed in the heating tube 12, avoiding the aluminothermic reaction from stopping and improving the practicality of the device.

[0033] Example 2 like Figures 7-10 As shown, a method for static splitting and directional demolition of pile heads includes the aforementioned static splitting and directional demolition device for pile heads, and further includes the following steps: Step 1: Drilling. After the pile head 1 is exposed, a circumferential line is laid out 5-10 cm above the predetermined height of the cast-in-place pile to locate the height of the demolition hole 7. A 3D laser scan is used to locate the distribution of the reinforcing bars 15 in the reinforcing cage, avoiding the position of the reinforcing bars 15. Then, evenly distributed demolition holes 7 are drilled radially along the pile head 1 in the circumferential direction of the laid-out line. High-pressure air hoses are then used to clean the demolition holes 7. Preferably, an induction groove is also created in the demolition hole 7. An L-shaped scraper or iron bar is used to scrape the inner wall of the demolition hole 7 along its length to create one or more inverted V-shaped or rectangular shallow grooves as induction grooves. The induction grooves can guide the direction of crack opening, further orienting the cracking of the pile head 1. Therefore, the induction grooves should not be located on the lower side of the inner wall of the demolition hole 7 to avoid the crack extending below the predetermined height of the cast-in-place pile. For pile heads 1 with a diameter less than three meters, the diameter of the demolition hole 7 is between 28-40 mm, and the length of the demolition hole 7 is [missing information - likely a percentage] of the diameter of the pile head 1. to The breaching holes 7 are arranged in a circumferentially without interconnection to avoid interference between the breaching pipes 2. Specifically, the breaching holes 7 can be evenly distributed circumferentially with breaching holes 7 of the same length, such as... Figure 9 As shown; alternatively, different lengths of the breaching holes 7 can be arranged at intervals, such as... Figure 10 As shown, the spaced-apart breaching holes 7 can get closer to the axis of the pile head 1. Step 2: Prepare the slurry. Prepare the fracturing agent slurry according to a calcium oxide to water weight ratio of 3:1, and stir it with a mixer until it reaches a uniform paste consistency. Preferably, additional... The liquid polycarboxylate superplasticizer is added at a rate of 5 ml per kilogram of slurry to extend the initial setting time, facilitate filling of slurry in multiple locations, and avoid excessive differences in state between the first and last slurry filled. Step 3: Prepare the powder. Mix the aluminum powder with the powdered metal oxide evenly. The metal oxide is selected from among iron(III) oxide, iron(II) oxide and copper oxide. Iron(III) oxide is preferred because it reacts quickly and is economical. More preferably, a small amount of sodium chloride powder can be added to accelerate the reaction. Step 4: Making the tube. Cut the breaking tube 2 with scissors according to the depth of the breaking hole 7, so that the length of the breaking tube 2 is 2-3 cm less than the depth of the corresponding breaking hole 7. Then, completely immerse the broken tube 2 of the cut length into the slurry, so that the cavity of the breaking tube 2 is filled with the breaking agent slurry. Then, seal both ends of the breaking tube 2 in the slurry with the tube plug 6 to prevent the slurry from spilling out when the breaking tube 2 moves. Step 5: Filling with powder. Cut the heating tube according to the depth of the drilled hole 7, so that the length of the heating tube is 3-5 cm longer than the depth of the corresponding drilled hole 7. Place the conical plug at one end of the heating tube, and then insert a baffle of the same length as the heating tube into the heating tube. Then fill the left or right cavity of the baffle with thermite powder through the funnel. Finally, seal the heating tube with another conical plug to prevent the powder from spilling out. Step Six: Filling the Holes. Remove the breaching tube 2 from the slurry and insert it into the corresponding breaching hole 7. During the movement of the breaching tube 2, ensure that the directional hole 5 is always facing upwards to prevent slurry spillage. Remove the hole-covering strip when the breaching tube 2 is inserted into the breaching hole 7. After insertion, the breaching tube 2 can be slightly rotated to adjust the orientation of the directional hole 5, but the rotation angle should not exceed 90° to prevent excessive slurry from flowing out of the directional hole 5 and affecting the breaching effect. Then, fully insert the breaching tube 2 into the breaching hole 7, and then remove it. The heating tube of the broken hole 7 should be inserted into the conical plug at one end of the heating tube and through the plug 6 on the outside of the broken tube 2. Then continue to insert it inward until the conical plug on the inside of the broken hole 7 is inserted into the plug 6 at the other end to limit and support the heating tube. While the heating tube is inserted into the broken tube 2, it occupies the space of the cavity of the broken tube 2 so that the slurry in the cavity is squeezed out from the directional hole 5, so that the slurry flows into the gap between the outer wall of the broken tube 2 and the broken hole 7 to fully fill the broken hole 7. Step 7: Demolition. Fill all the demolition holes 7, and then surround the outside of the demolition holes 7 with a circumferential restraint strap 16. The restraint strap 16 can be made of steel strip or steel wire to prevent the items in the demolition holes 7 from being ejected, but should avoid affecting the position of the heating tubes. Then remove the conical plugs at the outer ends of all the heating tubes and connect this end of the heating tube to the output end of the fiber laser so that the laser can ignite the thermite powder. After connecting all the heating tubes to the fiber laser, the staff retreats to a safe distance and uses a laser of more than one kilowatt to ignite the thermite in multiple heating tubes within a microsecond error range, so as to achieve simultaneous and rapid demolition of multiple demolition holes 7. Step 8: Cleaning. Spray the broken pile head 1 fragments with alkaline sodium carbonate solution to neutralize the residue from the crushing reaction, and then clean up the pile head 1 fragments. For the small amount of pile head 1 remaining above the predetermined height of the cast-in-place pile, use other methods to cut it off precisely, such as water jet or handheld cutting machine, and clean up the waste material to complete the high-quality and high-efficiency demolition of pile head 1.

[0034] Example 3 When breaking down a pile head 1 with a diameter greater than three meters, it is not only necessary to open a breaking hole 7 in the radial direction of the pile head 1, but also to open a breaking hole 7 in the axial direction in the middle of the pile head 1, so as to make the breaking effect better and more efficient. Specifically, in step one of embodiment two, the breaking holes 7 in the radial direction of the pile head 1 are arranged in a way that breaks holes 7 of different lengths are spaced apart. Then, several corresponding axial breaking holes 7 are opened directly above the breaking holes 7 in the radial direction of the pile head 1. The depth of the axial breaking holes 7 is 0.8 times the distance from the radial breaking hole 7 to the top of the pile head 1. The axial breaking holes 7 are opened to avoid the steel bars 15 of the steel cage, so that there is no connection between all the breaking holes 7. In step six of embodiment two, it is not necessary to place the breaking pipe 2 in the axial breaking hole 7. The breaking agent slurry can be directly poured into the axial breaking hole 7, and the top liquid level of the slurry is 2-3 cm lower than the opening. Then, the heating element is placed in the axial breaking hole 7. Preferably, the opening of the axial breaking hole 7 is sealed with clay or foam.

[0035] Example 4 For concrete piles with excessively high pile heads, a single row of radial breaking holes 7 may not meet the needs of rapid breaking of the pile head 1. Therefore, multiple rows of radial breaking holes 7 can be opened in the axial direction of the pile head 1. Preferably, a row of radial breaking holes 7 is set every 0.8 meters. Except for the bottom row of breaking holes 7, the guide grooves in the other breaking holes 7 can be on the lower side of the inner wall of the breaking hole 7 to improve the quality and efficiency of breaking the pile head 1.

[0036] All aspects not detailed in this invention are conventional technical means known to those skilled in the art.

[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0040] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A static splitting and directional demolition device for pile heads, installed inside a concrete pile head (1), characterized in that, It includes a breaking tube (2), and a receiving cavity (4) is provided inside the breaking tube (2) for accommodating the breaking agent and the heating element (3). A directional hole (5) is opened through the side wall of the breaking tube (2) along the length direction of the breaking tube (2). Pipe plugs (6) are detachably provided at both ends of the breaking tube (2) for sealing both ends of the breaking tube (2). The heating element (3) is provided on the pipe plug (6), and the breaking agent can cover the part of the heating element (3) located in the receiving cavity (4).

2. The static splitting and directional demolition device for pile heads (1) according to claim 1, characterized in that: The demolition tube (2) is made of plastic and has a diameter of 26-38 mm. The length of the demolition tube (2) is cut according to the depth of the corresponding demolition hole (7) drilled on the concrete pile head (1). The demolition tube (2) is rotated and set in the demolition hole (7) of the concrete pile head (1) to adjust the direction of the directional hole (5), and the axis of the demolition tube (2) is perpendicular to the axis of the concrete pile head (1).

3. A static splitting and directional demolition device for pile heads (1) according to claim 2, characterized in that: The breaking agent is a mixture of calcium oxide and water, which can completely fill the containment cavity (4) and can flow out from the directional hole (5).

4. A static splitting and directional demolition device for pile heads (1) according to claim 3, characterized in that: The axis of the directional hole (5) is perpendicular to the axis of the demolition tube (2). Several directional holes (5) are evenly arranged along the length of the demolition tube (2), and the axes of the directional holes (5) are all located in the same plane.

5. A static splitting and directional demolition device for pile heads (1) according to claim 4, characterized in that: A covering strip (8) is provided on the directional hole (5). The covering strip (8) is used to temporarily cover the directional hole (5) before the breaking tube (2) is inserted into the breaking hole (7).

6. A static splitting and directional demolition device for pile heads (1) according to claim 4, characterized in that: The pipe plug (6) is made of rubber and includes a sealing section and an outer sealing section. Multiple circumferential sealing bands (9) are arranged axially on the outer side of the sealing section. The diameter of the sealing band (9) is larger than the inner diameter of its corresponding broken pipe (2). An insertion end (10) is provided at the end of the sealing section away from the outer sealing section. The diameter of the outer sealing section is not less than the inner diameter of its corresponding broken pipe (2). Friction grooves (11) are arranged circumferentially on the outer side of the outer sealing section to increase friction. The middle part of the pipe plug (6) is used for the penetration of the heating element (3) and can support the heating element (3).

7. A static splitting and directional demolition device for pile heads (1) according to claim 6, characterized in that: The heating element (3) includes a heating tube (12), the diameter of which is smaller than that of the breaking tube (2). The thermite is placed inside the heating tube (12). A conical plug (13) is provided at one end of the heating tube (12). The conical plug (13) is conical in shape and can penetrate the tube plug (6) so that the tube plug (6) supports the heating tube (12). The other end of the heating tube (12) is connected to the output end of a fiber laser. The fiber laser is used to ignite the thermite inside the heating tube (12).

8. A static splitting and directional demolition device for pile heads (1) according to claim 7, characterized in that: The heating tube (12) is made of graphite tube. A baffle (14) is set in the inner cavity of the graphite tube along the length direction. The length of the baffle (14) is the same as the length of the heating tube (12), and the width of the baffle (14) is the same as the inner diameter of the graphite tube, so as to divide the inner cavity of the graphite tube into a left cavity and a right cavity. The thermite fills the left cavity or the right cavity.

9. A method for static splitting and directional demolition of pile heads, comprising the static splitting and directional demolition device for pile heads as described in claim 7, characterized in that, Includes the following steps: Step 1: Drilling. After the pile head is exposed, lay out the circumferential positioning at a position 5-10 cm above the predetermined height of the cast-in-place pile. Use three-dimensional laser scanning to locate the distribution of the reinforcing bars (15) in the reinforcing cage, avoiding the position of the reinforcing bars (15). Then, drill evenly distributed breaking holes (7) along the radial direction of the pile head in the circumferential direction of the laid-out line. Then clean the breaking holes (7). The diameter of the breaking holes (7) is 28-40 mm, and the length of the breaking holes (7) is within the diameter of the pile head. ~ Between them, and the breaching holes (7) are not connected to each other; Step 2: Prepare the slurry. Prepare the fracturing agent slurry with a weight ratio of calcium oxide to water of 3:1, and stir until it becomes a uniform paste. Step 3: Prepare the powder mixture. Mix the aluminum powder with the powdered metal oxides evenly. The metal oxides can be selected from among iron(III) oxide, iron(II) oxide, and copper oxide. Step 4: Making the tube. Cut the breaking tube (2) according to the depth of the broken hole (7) so that the length of the breaking tube (2) is 2-3 cm less than the depth of the corresponding broken hole (7). Immerse the broken tube (2) of the cut length completely into the slurry so that the cavity (4) of the breaking tube (2) is filled with the breaking agent slurry. Then, seal both ends of the breaking tube (2) in the slurry with the tube plug (6) to prevent the slurry from spilling out when the breaking tube (2) moves. Step 5: Filling with powder. Cut the heating tube according to the depth of the hole to make the length of the heating tube 3-5 cm longer than the depth of the corresponding hole. Place the cone plug (13) at one end of the heating tube. Then insert a baffle of the same length as the heating tube into the heating tube. Then fill the left or right cavity of the baffle with the thermite powder through the funnel. Then seal the heating tube with another cone plug (13) to prevent the powder from spilling out. Step Six: Filling the Hole. Remove the broken tube from the slurry and fill it into the corresponding broken hole. During the movement of the broken tube, keep the directional hole facing upward to prevent the slurry from spilling out. Remove the hole cover strip when inserting the broken tube into the broken hole. After the broken tube is inserted, you can slightly rotate the broken tube to adjust the orientation of the directional hole. Then, fully insert the broken tube into the broken hole. Next, take out the heating tube corresponding to the broken hole. Insert the conical plug at one end of the heating tube and pass through the plug on the outside of the broken tube. Then continue to insert it inward until the conical plug on the inside of the broken hole is inserted into the plug on the other end to limit the heating tube. When the heating tube is inserted into the broken tube, it occupies the space of the broken tube's receiving cavity to squeeze the slurry in the receiving cavity out of the directional hole, so that the slurry flows into the gap between the outer wall of the broken tube and the broken hole. Step 7: Demolition. Fill all the demolition holes, and then set up a circumferential restraint strap (16) around the outside of the demolition holes. The restraint strap (16) is used to prevent the items in the demolition holes from being ejected. Then remove the cone plugs at the outer ends of all the heating tubes and connect the end to the output end of the fiber laser so that the laser can ignite the thermite powder. After connecting all the heating tubes to the fiber laser, the staff retreated to a safe distance, the laser ignited, and the synchronous and rapid demolition of multiple demolition holes was completed. Step 8: Cleaning. Spray the broken pile head fragments with an alkaline sodium carbonate solution to neutralize the residue from the crushing reaction, then clean up the pile head fragments. For the small amount of pile head remaining above the predetermined height of the cast-in-place pile, use other methods such as water jet cutting and handheld cutting machines for precise removal and clean up the waste, thus completing the removal of the pile head.

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