Blasting tube for foundation reinforcement and method for reinforcing foundation through air blasting

Abstract

The blasting tube comprises a tube body and an air leakage head, a high-pressure air tube is arranged in the tube body, the air leakage head is fixed to one end of the tube body, a hole is formed in the side face of the other end of the tube body, and a shearing piece is arranged at the end, facing the air leakage head, of the high-pressure air tube. The high-pressure air pipe is connected with a hose, the hose penetrates through a hole in the side face of the pipe body, an adapter is arranged at the outer end of the hose, an air leakage plate is arranged on the end face of the air leakage head, and a plurality of bottom end air leakage holes communicated with the interior of the air leakage head are formed in the air leakage plate. The method has the beneficial effects of being high in safety, environmentally friendly, low in cost, high in efficiency and good in soil body reinforcing effect.

Description

Technical Field

[0001] The invention relates to the field of engineering construction, in particular to a blasting tube for foundation reinforcement and a method for strengthening the foundation by air blasting. Background Art

[0002] With the rapid development of my country's national economy, my country's civil engineering construction has developed rapidly since the 1990s. The requirements of various buildings and structures for foundations have become prominent, mainly stability problems, deformation problems and permeability problems. When the natural foundation cannot meet the requirements of the building (structure) in the above three aspects, it is necessary to treat the natural foundation. According to the experimental research and engineering practice in the past four decades, the dynamic tamping method is more effective in strengthening the foundation. Dynamic tamping construction is a rapid consolidation method of the foundation that quickly tamps the foundation with a heavy hammer to improve the bearing capacity of the soft foundation. The defects of traditional dynamic tamping technology are: traditional dynamic tamping technology usually only considers the treatment of 6-8 meters. If the treatment depth needs to be increased, the method of increasing the hammer energy, increasing the hammer weight and increasing the height of the tamping hammer is often adopted. This not only increases the safety risk sharply, reduces the construction efficiency, and increases the construction cost, but also greatly reduces the guarantee rate of the traditional dynamic tamping treatment effect as its depth increases. Summary of the invention

[0003] The idea of ​​the present invention is that the traditional dynamic compaction technology usually only considers the treatment of 6-8 meters. If the liquefied soil layer is buried deeper and the treatment depth needs to be increased, the method of increasing the hammer energy, increasing the hammer weight and raising the height of the rammer is often adopted. This not only increases the safety risk sharply, reduces the construction efficiency, and increases the construction cost, but also greatly reduces the guarantee rate of the traditional dynamic compaction treatment effect as the depth increases. Using air blasting technology, at the boundary point under the dynamic compaction treatment depth, the blasting point is arranged by drilling, and the explosion is used to produce the compaction effect of squeezing the soil body and the reinforcement effect of vibration on the soil body, instead of using its traditional destructive force. By arranging release pipes, semicircular vents, air ducts, explosion time, explosion energy, explosion range and other methods, effective blasting of fixed-point and quantitative foundation treatment is achieved.

[0004] The principle of air blasting is: use an air compressor to compress the air to a certain pressure, and then transport it to the pit through a pipeline for blasthole filling and ignition, and use the huge air pressure energy to crush rocks and strata to complete a specific crushing project. Air blasting projects have the advantages of low noise, low vibration, no explosives, environmental protection and pollution-free, so they are widely used in cities, hydropower stations, and large-scale foundation projects. After drilling in the soil medium, the high-pressure gas is released instantly, generating a large amount of high-pressure gas and high-energy shock waves, causing the soil skeleton around the borehole to be strongly deformed and damaged. Then, the high-pressure gas shock wave is transmitted to the soil around the borehole and propagates deep inside the soil in the form of stress waves. Under the action of the high-pressure air blasting stress wave, the soil medium unit undergoes tangential stretching and radial compression. When the tangential tensile stress is greater than the dynamic tensile strength of the soil, radial cracks will be generated in the soil and expand with the propagation of the blasting stress wave. When the blasting tangential tensile stress decays to a level lower than the dynamic tensile strength of the soil medium, the cracks stop expanding. As the stress wave of high-pressure air blasting propagates and the cracks expand, the volume of high-pressure air expands rapidly, filling the radial crack space. Under the sharp action of high-pressure gas, the soil cracks continue to expand, forming a cross crack network around the blasting hole.

[0005] The ambient air is first compressed by the high-pressure air compressor unit, and the compressed air sent by the high-pressure air compressor unit enters the booster pump through the high-pressure gas cylinder for compression. The compressed air pressure reaches 70MPa. When the pressure reaches the ultimate strength that the shear plate in the blasting device can withstand, the shear plate is damaged, and the gas is suddenly and violently released, which has a huge impact effect on the soil.

[0006] The technical solution adopted by the present invention is: a blasting tube for foundation reinforcement, comprising a tube body and a gas release head, the tube body having a high-pressure air pipe, the gas release head being fixed to one end of the tube body, the side of the other end of the tube body having a hole, the high-pressure air pipe having a shear piece at one end facing the gas release head, a hose being connected to the high-pressure air pipe, the hose passing through the hole on the side of the tube body, the outer end of the hose having an adapter, a gas release plate being arranged on the end face of the gas release head, the gas release plate having a plurality of bottom gas release holes communicating with the interior of the gas release head.

[0007] Optionally, the air release plate is a spherical structure with a convex surface facing the outside of the air release head, and the bottom air release holes are evenly distributed on the spherical structure.

[0008] A blasting tube for foundation reinforcement comprises a tube body and a gas relief head, wherein the tube body is provided with a high-pressure air pipe, the gas relief head is fixed to one end of the tube body, a plurality of side gas relief holes are arranged on the side of the gas relief head around its axis, the side of the other end of the tube body is provided with a hole, a shear piece is provided on the high-pressure air pipe at one end facing the gas relief head, a hose is connected to the high-pressure air pipe, the hose passes through the hole on the side of the tube body, an adapter is provided at the outer end of the hose, an inclined air guide tube is provided on the side gas relief hole, and the outlet of the air guide tube is inclined toward the end direction of the gas relief head.

[0009] Optionally, the end of the tube body and the end of the air release head have a slot and an insert block respectively, the slot and the insert block are adapted in size, and the side of the slot and the side of the insert block both have pin holes.

[0010] A method for strengthening a foundation by air blasting using the blasting tube for strengthening a foundation as described above comprises the following steps:

[0011] ⑴ Drill blast holes on the surface of the soil to be reinforced. The depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil;

[0012] (2) Connect the tail end of a single blasting tube to a steel pipe. The total length of the steel pipe and the blasting tube is greater than the depth of the blasthole. The steel pipe is connected to the clamp on the lifting rod. The blasting tube's air discharge head faces the bottom of the blasthole. Slowly put it into the blasthole, keeping the adapter of the hose on the blasting tube outside the blasthole. When the lifting rod contacts the ground, the blasting tube is suspended in the blasthole. At this time, the end of the steel pipe connected to the blasting tube is in the blasthole, and the other end extends above the ground.

[0013] ⑶ Connect the adapter to the external high-pressure air delivery equipment, fill and block the blast hole equipped with the blasting tube, and detonate the blasting tube by delivering high-pressure air to the high-pressure air pipe in the blasting tube;

[0014] (4) After the detonated blasting tube is taken out from the blast hole, small particles of building materials are injected into the gaps in the soil body caused by blasting through the blast hole and the air duct;

[0015] ⑸ After the site is leveled, conventional compaction construction is carried out.

[0016] Optionally, the air intake holes are arranged on the fissure area after blasting.

[0017] Optionally, the material used to fill the blasthole in step (3) is a mixture of slag, clay and rock powder, and the small-particle building material is a mixture of one or more of soil, gravel, sand, slag and rock powder.

[0018] A method for strengthening a foundation by air blasting using the blasting tube for strengthening a foundation as described above comprises the following steps:

[0019] ⑴ Drill blast holes on the surface of the soil to be reinforced. The depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil;

[0020] (2) Connect the tube bodies of multiple blasting tubes in series through the plug blocks at the ends of the tube bodies and the slots on the end faces of the air relief heads. Adjacent blasting tubes are fixed to each other. The total length of the multiple blasting tubes connected in series is greater than the depth of the blasthole. The blasting tube at one end of the multiple blasting tubes connected in series is a blasting tube with an air relief plate at the end. The air relief holes of the remaining blasting tubes are all located on the sides of the air relief heads. The blasting tube with the air relief plate at the end faces the bottom of the blasthole. The clamps on the lifting rods clamp the multiple blasting tubes connected in series, and slowly put the blasting tubes connected in series into the blasthole, keeping the adapter on the hose of the blasting tube outside the blasthole. When the multiple blasting tubes connected in series reach a predetermined depth, the lifting rod contacts the ground, and the blasting tubes connected in series are suspended in the blasthole. At this time, one end of the blasting tube located at the top of the blasting tubes connected in series extends above the ground.

[0021] ⑶Fill and block the blast hole equipped with the blasting tube, connect the hose joint on the blasting tube to the external high-pressure air delivery equipment, and detonate the blasting tube by delivering high-pressure air to the high-pressure air pipe in the blasting tube;

[0022] (4) After the detonated blasting tube is taken out from the blast hole, small particles of building materials are injected into the gaps in the soil body caused by blasting through the blast hole and the air duct;

[0023] ⑸ After the site is leveled, conventional compaction construction is carried out.

[0024] Optionally, the air intake holes are arranged on the fissure area after blasting.

[0025] Optionally, the material used to fill the blasthole in step (3) is a mixture of slag, clay and rock powder, and the small-particle building material is a mixture of one or more of soil, gravel, sand, slag and rock powder.

[0026] The advantages and positive effects of the present invention are:

[0027] 1. Air blasting creates cavities underground, which can replace a portion of high-quality soil to achieve the replacement foundation treatment effect. Blasting produces soil extrusion to achieve the foundation treatment effect;

[0028] 2. Generate vibration waves underground to achieve the effect of soil liquefaction foundation treatment, and achieve deep foundation treatment that cannot be handled by strong compaction;

[0029] 3. It can effectively control the residual settlement of foundation treatment, overcome the deficiency that ordinary strong compaction can only handle 6-8 meters of thickness, and achieve the purpose of deep foundation treatment;

[0030] 4. Use spherical air vents or side air vents in combination with oblique air guides, and set air guide holes within the crack area on the ground, so that most of the energy during blasting acts on the lower part, with less impact on the upper soil, achieving effective soil foundation treatment results;

[0031] 5. Air blasting achieves effective blasting below the critical foundation point of strong compaction. High-quality small-particle engineering building materials are replaced through blast holes and air ducts. Strong compaction foundation treatment is then used to strengthen the effect of air blasting on the upper soil, achieving effective reinforcement of shallow and deep layers of the soil and further reducing residual settlement. This effective combination makes foundation treatment more efficient and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of an implementation mode of the medium-speed tube array of the present invention;

[0033] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle air release plate;

[0034] Figure 3 It is a structural schematic diagram of another embodiment of the tube array in the present invention;

[0035] Figure 4 It is a schematic diagram of the distribution of rupture areas after blasting;

[0036] Figure 5 It is a schematic diagram of the layout of a single tube for blasting;

[0037] Figure 6 It is a schematic diagram of the arrangement of multiple blasting tubes in series for blasting;

[0038] Figure 7 It is a schematic diagram of the dynamic compaction construction process;

[0039] In the figure: 1-tube body; 1-1, plug; 2, vent head; 2-1, side vent hole; 2-2, slot; 2-3, air guide tube; 3, threaded connection; 4, vent plate; 4-1, bottom vent hole; 5, hose; 6, adapter; 7, crushing area; 8, crack area; 9, vibration area; 10, ground; 11, lifting rod; 12, steel pipe; 13, critical soil depth; 14, first air-induced tube; 15, second air-induced tube; 16, third air-induced tube. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] like Figure 1 , Figure 2 As shown, the present invention provides a blasting tube for foundation reinforcement, including a tube body 1 and a gas release head 2, wherein the tube body 1 has a high-pressure air pipe, the gas release head 2 is fixed to one end of the tube body 1, and the side surface of the other end of the tube body 1 has a hole, and the high-pressure air pipe has a shear piece at one end facing the gas release head 2, and the high-pressure air pipe is connected to a hose 5, and the hose 5 passes through the hole on the side surface of the tube body 1, and the outer end of the hose 5 has an adapter 6, and a gas release plate 4 is arranged on the end surface of the gas release head 2, and the gas release plate 4 has a plurality of bottom gas release holes 4-1 that penetrate the inside of the gas release head 2.

[0042] The air release plate 4 is a spherical structure with a convex surface facing the outside of the air release head 2, and the bottom air release holes 4-1 are evenly distributed on the spherical structure.

[0043] The blasting tube can be used for single blasting. The difference between the blasting tube and the air-induced column tube in the prior art lies in the arrangement position of the air leakage hole. The blasting purpose of the air-induced column tube in the prior art is to crush the soil. Therefore, its air leakage hole is arranged on the side of the air leakage head of the tube body, and the axis of the air leakage hole is perpendicular to the axis of the tube body, so that the high-pressure air is dispersed as much as possible toward the surroundings of the column tube during blasting to achieve the purpose of crushing the soil. The blasting purpose of the blasting tube of the present invention is to compress the soil below the blasting tube while minimizing the impact on the soil above. Therefore, the bottom air leakage hole 4-1 of the present invention is arranged at the lower end of the air leakage head 2, and the surface of the air leakage plate 4 is a spherical surface, so that the high-pressure air ejected from the bottom air leakage hole 4-1 is in a downward divergent state, thereby achieving the purpose of compacting the soil below.

[0044] like Figure 3 As shown, a blasting tube for foundation reinforcement, which can be used for blasting as a single tube or in series with a blasting tube with an air vent at the lower end, comprises a tube body 1 and an air vent head 2, wherein the tube body 1 has a high-pressure air pipe, the air vent head 2 is fixed to one end of the tube body 1, a plurality of side air vent holes 2-1 are arranged on the side of the air vent head 2 around its axis, the side of the other end of the tube body 1 has a hole, a shear piece is arranged on the end of the high-pressure air pipe facing the air vent head 2, a hose 5 is connected to the high-pressure air pipe, the hose 5 passes through the hole on the side of the tube body 1, the outer end of the hose 5 has an adapter 6, the side air vent hole 2-1 has an inclined air guide tube 2-3, and the outlet of the air guide tube 2-3 is inclined toward the end of the air vent head 2.

[0045] The ends of the tube body 1 and the end of the air release head 2 are respectively provided with a slot 2-2 and an insert block 1-1, the sizes of the slot 2-2 and the insert block 1-1 are adapted, and the sides of the slot 2-2 and the side of the insert block 1-1 are provided with pin holes.

[0046] The blasting tube uses the air guide pipe 2-3 welded on the side air leakage hole 2-1 to guide the injection direction of the high-pressure air during blasting toward the lower soil, so as to achieve the purpose of compacting the lower soil. The slot 2-2, the plug 1-1 and the pin hole are arranged for connecting multiple blasting tubes in series. When used in conjunction with a blasting tube with a bottom air leakage hole 4-1, a plug 1-1 adapted to the slot 2-2 needs to be arranged on the blasting tube with the bottom air leakage hole 4-1.

[0047] The present invention relates to a method for strengthening foundation by air blasting using the above-mentioned blasting tube. This embodiment introduces a method for blasting with a single tube, comprising the following steps:

[0048] (1) Drilling blast holes on the surface of the soil to be reinforced, the depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil, and the air holes are arranged on the fracture area 8 after blasting;

[0049] ⑵ If Figure 5 As shown, the tail end of a single blasting tube is connected to a steel tube 12, the total length of the steel tube 12 and the blasting tube is greater than the depth of the blasthole, the steel tube 12 is connected to the clamp on the lifting rod 11, the air release head 2 of the blasting tube is facing the bottom of the blasthole, and it is slowly put into the blasthole, keeping the adapter on the blasting tube outside the blasthole, when the lifting rod 11 contacts the ground 10, the blasting tube is suspended in the blasthole, at this time, one end of the steel tube 12 connected to the blasting tube is located in the blasthole, and the other end extends above the ground 10;

[0050] ⑶ Fill and plug the blast hole equipped with the blasting tube, connect the adapter 6 on the blasting tube to the external high-pressure air delivery equipment, and deliver high-pressure air to the high-pressure air pipe in the tube body. The air pressure in the high-pressure air pipe increases to break the shear piece on the high-pressure air pipe, thereby detonating the blasting tube;

[0051] (4) After the detonated blasting tube is taken out from the blast hole, a mixture of one or more of soil, gravel, sand, slag and rock powder is injected into the voids in the soil body caused by blasting from the blast hole and the air inlet hole;

[0052] ⑸ Carry out conventional compaction construction.

[0053] The material used to fill the blasthole in step (3) is a mixture of one or more of slag, clay, and rock powder.

[0054] The present invention relates to a method for strengthening a foundation by air blasting using the above-mentioned blasting tube. This embodiment introduces a method for blasting by connecting multiple blasting tubes in series, including the following steps:

[0055] ⑴ Drill blast holes on the surface of the soil to be reinforced. The depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil;

[0056] ⑵ If Figure 6 As shown, the tube bodies 1 of multiple blasting tubes are connected in series, and adjacent blasting tubes are fixed to each other through slots 2-2, plug blocks 1-1 and fixing pins passing through pin holes. The total length of the multiple blasting tubes connected in series is greater than the depth of the blasthole. The blasting tube at one end of the multiple blasting tubes connected in series is a blasting tube with an air release plate 4 at the end, and the air release holes of the remaining blasting tubes are all located on the side of the air release head 2. The blasting tube with the air release plate 4 at the end faces the bottom of the blasthole. The clamp on the lifting rod 11 clamps the multiple blasting tubes connected in series, and slowly puts the blasting tubes connected in series into the blasthole, keeping the adapter on the blasting tube outside the blasthole. When the multiple blasting tubes connected in series reach a predetermined depth, the lifting rod 11 contacts the ground 10, and the blasting tubes connected in series are suspended in the blasthole. At this time, one end of the blasting tube located at the top of the blasting tubes connected in series extends above the ground 10.

[0057] ⑶Fill and plug the blastholes equipped with blasting tubes, connect the adapters on the series-connected blasting tubes to the external high-pressure air delivery equipment, and deliver high-pressure air to the high-pressure air pipes in the tube body. The air pressure in the high-pressure air pipes increases, breaking the shearing pieces on the high-pressure air pipes, thereby detonating the blasting tubes;

[0058] (4) After the detonated blasting tube is taken out from the blast hole, a mixture of one or more of soil, gravel, sand, slag and rock powder is injected into the voids in the soil body caused by blasting from the blast hole and the air duct hole;

[0059] ⑸ Carry out conventional compaction construction.

[0060] The principle of the above-mentioned method of strengthening the foundation by air blasting using a blasting tube is that: air blasting creates a cavity underground, and a mixture of one or more of soil, gravel, sand, slag, and rock powder can be poured into the cavity through the blasthole and the air duct hole to replace a part of the high-quality soil, thereby achieving a replacement foundation treatment effect. The blasting produces compression on the lower soil layer, and the setting of the air duct hole reduces the force of the explosion on the upper soil layer, thereby achieving a foundation treatment effect.

[0061] Vibration waves are generated underground to achieve the effect of soil liquefaction foundation treatment, and can be used to treat deep foundations that cannot be treated by strong compaction;

[0062] It can effectively control the residual settlement of foundation treatment, overcome the deficiency of ordinary strong compaction that can only handle 6-8 meters of thickness, and achieve deep foundation treatment;

[0063] High-pressure air is suddenly released in the blasthole and impacts the soil to generate stress waves. During the propagation of stress waves in the soil, cracks in the soil are generated, expanded, extended and connected.

[0064] In the crushing area, the high-pressure gas released instantly from the blasting port acts on the wall of the blasthole, generating a blasting stress wave. Since the impact force of the gas blasting is much greater than the dynamic compressive strength of the soil, the soil skeleton is severely deformed and damaged under the action of the blasting stress wave; the soil near the blasting hole is radially compressed and tangentially stretched, the medium unit moves, the soil breaks, and the original cracks expand. As the blasting stress wave propagates and attenuates, when its strength is no longer enough to break the soil, the soil medium unit will only vibrate, and the blasting stress wave propagates in the form of seismic waves until it disappears.

[0065] The blasthole is designed to be 1m deep. After blasting, the blaster and steel pipe 11 are pulled out, the hole is sealed in time, and the extraction pipeline is connected for extraction. The extraction concentration, negative pressure and other indicators of the blasting hole are measured twice a day in the morning and afternoon.

[0066] For the case where multiple blasting tubes are connected in series: first connect the first air blasting tube 14 and the second air blasting tube 15, and insert the fixing pin; connect the adapters on the first air blasting tube 14 and the second air blasting tube 15 to the high-pressure air delivery equipment, first insert the two connected blasting tubes into the blast hole, before inserting, first connect the clamp on the lifting rod 11 to the second air blasting tube 15, and then insert it into the blast hole, use the lifting rod 11 to support the blasting tube to prevent the blasting tube from falling into the blast hole; connect the third air blasting tube 16 to the second air blasting tube 15, Clamp the third air blasting tube 16 with the clamp on the second lifting rod 11; then pull out the first lifting rod 11, and put the blasting tube into the blasthole; repeat the above steps to connect the remaining blasting tubes; use drilled stone slag, clay, rock powder, etc. to fill, and the filling length is strictly carried out according to the blasting design to ensure that the blasting tube cannot fly; turn on the external high-pressure air conveying equipment to inflate the blasting tubes in series. When the air pressure in the blasting tube is greater than the bearing pressure of the shear piece, the shear piece ruptures, and the high-pressure air rushes out of the vent hole instantly to blast.

[0067] After blasting, the blasting tube should be recovered for next use.

[0068] After the blasting construction is completed, the strong compaction technology, such as Figure 7 As shown, the steps include: ⑴ If there is water accumulation on the surface of the site, it should be discharged in time, and pre-treatment methods such as mechanical walking disturbance can be adopted on site for drainage; ⑵ The site is leveled, and the leveling elevation is 7.2-7.35m; ⑶ Backfill 0.5m of medium-coarse sand, with an error of ±5; ⑷ Install plastic drainage boards, arranged in a square, with a spacing of 1m, and the bottom elevation is shown in the drainage board layout diagram; ⑸ Backfill 1m of mountain soil; ⑹ Excavate drainage ditches around the outer periphery of the reinforcement area, with a ditch depth of not less than 1.3m (below the top surface of the blown fill), and the specific width can be determined according to the actual situation on site; ⑺ Wait until the water level is about to reach The depth below the rammed surface is not less than 2m. First, full-line construction is carried out, and then spot ramming construction is carried out. The ramming energy is 800kN.m-2000kN.m. The number of ramming times and other processes refer to the strong ramming test ramming process and detection point layout diagram; ⑻ During spot ramming construction, if there is water in the ramming pit, it should be discharged in time. If the ramming pit is deep, sandy soil should be backfilled before subsequent construction; ⑼ After the strong ramming is completed, the site is leveled and the last full ramming is carried out; ⑽ Before strong ramming, it should be ensured that the pore water pressure dissipates by 75%, and the water level will be no less than 2m below the ramming surface. The full ramming energy is 500kN.m. The hammer print overlaps 1 / 4, and two hits are made each time; ⑾ Finally, use a 200kN vibratory roller to roll 6-8 times, and the compaction degree is not less than 90%.

[0069] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A blasting tube for foundation reinforcement, comprising a tube body and a gas release head, wherein the tube body is provided with a high-pressure gas pipe, the gas release head is fixed to one end of the tube body, the side surface of the other end of the tube body is provided with a hole, the high-pressure gas pipe is provided with a shearing piece at one end facing the gas release head, the high-pressure gas pipe is connected with a hose, the hose passes through the hole on the side surface of the tube body, and the outer end of the hose is provided with a conversion joint, characterized in that: An air release plate is arranged on the end surface of the air release head, and the air release plate has a plurality of bottom air release holes which are communicated with the interior of the air release head.

2. The blasting tube for foundation reinforcement according to claim 1, characterized in that: The degassing plate is a spherical structure with a convex surface facing the outside of the degassing head, and the bottom degassing holes are evenly distributed on the spherical structure.

3. A blasting tube for foundation reinforcement, comprising a tube body and a gas release head, wherein the tube body is provided with a high-pressure gas pipe, the gas release head is fixed to one end of the tube body, a plurality of side gas release holes are arranged on the side of the gas release head around its axis, the side of the other end of the tube body is provided with a hole, the high-pressure gas pipe is provided with a shearing piece at one end facing the gas release head, the high-pressure gas pipe is connected with a hose, the hose passes through the hole on the side of the tube body, and the outer end of the hose is provided with a conversion joint, characterized in that: The side air leakage hole is provided with an air guide pipe which is arranged obliquely, and the outlet of the air guide pipe is inclined toward the end direction of the air leakage head.

4. The blasting tube for foundation reinforcement according to claim 3, characterized in that: The end of the tube body and the end of the air release head are respectively provided with a slot and an insert block, the sizes of the slot and the insert block are adapted, and the side surfaces of the slot and the insert block are both provided with pin holes.

5. A method for strengthening a foundation by air blasting using a blasting tube for foundation reinforcement as claimed in any one of claims 1 to 4, comprising the following steps: ⑴ Drill blast holes on the surface of the soil to be reinforced. The depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil; (2) Connect the tail end of a single blasting tube to a steel pipe. The total length of the steel pipe and the blasting tube is greater than the depth of the blasthole. The steel pipe is connected to the clamp on the lifting rod. The blasting tube's air discharge head faces the bottom of the blasthole. Slowly put it into the blasthole, keeping the adapter of the hose on the blasting tube outside the blasthole. When the lifting rod contacts the ground, the blasting tube is suspended in the blasthole. At this time, the end of the steel pipe connected to the blasting tube is in the blasthole, and the other end extends above the ground. ⑶ Connect the adapter to the external high-pressure air delivery equipment, fill and block the blast hole equipped with the blasting tube, and detonate the blasting tube by delivering high-pressure air to the high-pressure air pipe in the blasting tube; (4) After the detonated blasting tube is taken out from the blast hole, small particles of building materials are injected into the gaps in the soil body caused by blasting through the blast hole and the air duct; ⑸ After the site is leveled, conventional compaction construction is carried out.

6. The blasting tube for foundation reinforcement according to claim 5, characterized in that: The air vents are arranged on the fissure area after blasting.

7. The blasting tube for foundation reinforcement according to claim 5, characterized in that: The material for filling the blasthole in step (3) is a mixture of slag, clay and rock powder, and the small-particle building material is a mixture of one or more of soil, gravel, sand, slag and rock powder.

8. A method for strengthening a foundation by air blasting using the blasting tube for foundation reinforcement according to any one of claims 1 to 4, comprising the following steps: ⑴ Drill blast holes on the surface of the soil to be reinforced. The depth of each blast hole is greater than the length of a single blasting tube, the inner diameter of the blast hole is greater than the outer diameter of a single blasting tube, and multiple air holes are arranged on the surface of the soil; (2) Connect the tube bodies of multiple blasting tubes in series through the plug blocks at the ends of the tube bodies and the slots on the end faces of the air relief heads. Adjacent blasting tubes are fixed to each other. The total length of the multiple blasting tubes connected in series is greater than the depth of the blasthole. The blasting tube at one end of the multiple blasting tubes connected in series is a blasting tube with an air relief plate at the end. The air relief holes of the remaining blasting tubes are all located on the sides of the air relief heads. The blasting tube with the air relief plate at the end faces the bottom of the blasthole. The clamps on the lifting rods clamp the multiple blasting tubes connected in series, and slowly put the blasting tubes connected in series into the blasthole, keeping the adapter on the hose of the blasting tube outside the blasthole. When the multiple blasting tubes connected in series reach a predetermined depth, the lifting rod contacts the ground, and the blasting tubes connected in series are suspended in the blasthole. At this time, one end of the blasting tube located at the top of the blasting tubes connected in series extends above the ground. ⑶Fill and block the blast hole equipped with the blasting tube, connect the hose joint on the blasting tube to the external high-pressure air delivery equipment, and detonate the blasting tube by delivering high-pressure air to the high-pressure air pipe in the blasting tube; (4) After the detonated blasting tube is taken out from the blast hole, small particles of building materials are injected into the gaps in the soil body caused by blasting through the blast hole and the air duct; ⑸ After the site is leveled, conventional compaction construction is carried out.

9. The blasting tube for foundation reinforcement according to claim 8, characterized in that: The air vents are arranged on the fissure area after blasting.

10. The blasting tube for foundation reinforcement according to claim 8, characterized in that: The material for filling the blasthole in step (3) is a mixture of slag, clay and rock powder, and the small-particle building material is a mixture of one or more of soil, gravel, sand, slag and rock powder.

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