CN116695684A - Steel sheet pile and steel sheet pile support secondary disease control construction method - Google Patents

Abstract

A steel sheet pile and a construction method for preventing and controlling secondary diseases of the steel sheet pile support, relating to the field of deep foundation pit construction using steel sheet piles for support, the steel sheet pile includes a main steel plate and a sand injection pipe and a water injection pipe arranged on the inner surface of the main steel plate , the sand injection pipe and the water injection pipe are arranged along the length direction of the main steel plate, the inner surface of the main steel plate and its lower part are provided with a mixing chamber, the lower ends of the sand injection pipe and the water injection pipe are connected with the mixing chamber, and the mixing chamber has water supply, sand The discharge port after mixing and the non-return component that can control the opening or closing of the discharge port. The invention can effectively suppress the ground subsidence and displacement caused by pile pulling, ensure the safe and normal use of buildings (structures), underground pipelines and other municipal facilities around the foundation pit, and can especially solve the problem of deep trenches under poor geological conditions. Secondary damage such as large deformation and uneven settlement caused by steel sheet pile support for trench excavation.

Description

A construction method for prevention and control of secondary diseases of steel sheet pile and steel sheet pile support

technical field

The invention relates to the field of deep foundation pit construction supported by steel sheet piles, in particular to a construction method for preventing and controlling secondary diseases of steel sheet piles and steel sheet piles.

Background technique

As a foundation pit support structure, steel sheet piles are widely used in urban construction projects because of their recyclability, low environmental pollution, and high construction efficiency.

After the foundation pit is backfilled in practical applications, the sheet piles need to be pulled out for reuse. At present, the soil hole backfill material after the pile is pulled out mainly adopts refilling sand, and when the geological condition of the pipeline is poor, injecting cement mortar can also be used.

At present, due to the vibration effect of steel pulling piles and the excessive soil of steel pulling piles, ground subsidence and displacement cause great harm to surrounding structures and roads, and affect the safety of adjacent original buildings, structures or underground pipelines. . According to the design plan, the soil holes left after the steel sheet piles are pulled out are treated with sand filling, but the soil holes are often blocked or collapsed due to the vibration of the steel sheet piles in poor ground, and the sand cannot be recharged at all. The surrounding roads slipped to the groove under the vehicle load and vibration, causing the road surface to settle and crack. Therefore, how to prevent or reduce the diseases caused by steel sheet pile construction is an urgent problem to be solved.

In the prior art, the Chinese invention patent with the application number 202210488499.X discloses a detachable steel sheet pile that can be synchronously grouted during the pile pulling process and its use method. The grouting channel for grouting, when in use, pass the grouting pipe to the pile tip along the grouting channel, start the pile pulling equipment, start the grouting pump after pulling up to a certain height, and open the lower cover under the impact of the slurry, While the main steel plate rises, the holes generated by the pile pulling can be filled in time.

However, the vibration generated during the pile pulling process will cause the hole after the pile is pulled to be filled with soil, especially in the working condition of muddy soil. In the hole, the mortar poured in the hole has no strength at the initial stage and will flow, so the mortar will be squeezed by the muddy soil after the liquefaction of the lower part and go back up, and the hole is not easy to be filled and dense; In the slurry method, the slurry needs to be mixed in advance, and the mixed slurry should be continuously stirred to prevent it from solidifying in advance. The process of continuous pile extraction takes a long time, consumes more energy, and the configured slurry will also appear. The amount does not match the demand when pulling out piles, resulting in waste of slurry, or stopping work to wait for re-batching, which affects production efficiency.

Contents of the invention

The present invention aims to provide a steel sheet pile and a steel sheet pile support secondary disease prevention construction method to solve the problem of how to prevent or reduce the disease caused by the steel sheet pile construction.

In order to solve the above technical problems, the specific solution adopted by the present invention is: a steel sheet pile, including a main steel plate and a sand injection pipe and a water injection pipe arranged on the inner surface of the main steel plate, the sand injection pipe and the water injection pipe are all along the length direction of the main steel plate Setting, the inner surface of the main steel plate and the lower part are provided with a mixing chamber, the lower ends of the sand injection pipe and the water injection pipe are connected with the mixing chamber, the mixing chamber has a discharge port for water supply and sand mixing, and can control the opening of the discharge port Or closed non-return components.

As a further optimization of the above technical solution, the non-return assembly includes a baffle and a control unit capable of controlling the baffle to open or close the discharge port.

As a further optimization of the above technical solution, the upper end of the baffle is rotatably connected to the side wall of the mixing chamber and located above the discharge port. The control unit includes a rotating shaft and a gear lever arranged on the rotating shaft. A torsion spring is connected between the rotating shaft and the gear lever. Under the torsion of the torsion spring, the gear rod can block the baffle at the discharge port, and the impact force of the material discharged from the mixing chamber can overcome the torsion of the torsion spring and push the baffle to move outward to open the discharge port.

As a further optimization of the above technical solution, the lower end of the baffle is rotatably connected to the side wall of the mixing chamber and located below the discharge port. The control unit is a pull rope connected to the inside of the baffle, and the end of the pull rope is connected by a sand injection pipe or a water injection pipe. After stretching out, it is fixed on the main steel plate.

As a further optimization of the above technical solution, the mixing chamber is wedge-shaped with a large top and a small bottom.

As a further optimization of the above technical solution, the sand injection pipes and water injection pipes are distributed in a V shape.

As a further optimization of the above technical solution, the sand inlet of the sand injection pipe and the water inlet of the water injection pipe are both lower than the upper edge of the main steel plate.

As a further optimization of the above technical solution, the cross-section of the main steel plate is trapezoidal, including the main steel plate and side steel plates oppositely arranged on both sides of the main steel plate, and the sand injection pipe and the water injection pipe are both arranged on the main steel plate.

A construction method for preventing and controlling secondary diseases of steel sheet pile support based on the above steel sheet piles, comprising the following steps,

S1: Connect the sand injection pipe and water injection pipe of the steel sheet pile to the dry sandblasting machine and the water pump respectively;

S2: Lift the steel sheet pile up first, then start the dry sandblasting machine and the water pump, the sand and water enter the mixing chamber for mixing, and the mixed sand and water mixture is vibrated and liquefied to be sprayed out through the outlet below, and filled in In the hole after the steel sheet pile is pulled out;

S3: Use sand to compact the top of the hole after the steel sheet pile is pulled out.

As a further optimization of the above technical solution, in step S2, after the steel sheet pile is lifted up by 20-40cm by the vibrating pile driver, the dry sandblasting machine is first turned on to supply air to the sand injection pipe, and the air pressure is maintained at 0.1-0.2MPa to inject sand into the sand injection pipe. Send sand in the pipe, and then spray according to the water pressure is 0.1MPa higher than the wind pressure, and the water-sand ratio is 0.8:1.

Compared with the prior art, the beneficial effects of the present invention are as follows:

The invention can effectively suppress the ground subsidence and displacement caused by pile pulling, ensure the safe and normal use of buildings (structures), underground pipelines and other municipal facilities around the foundation pit, and can especially solve the problem of deep trenches under poor geological conditions. Secondary damage such as large deformation and uneven settlement caused by steel sheet pile support for trench excavation.

The construction method of the present invention mainly adopts strong sand washing measures to realize disease prevention and control during the pile pulling process, adopts adding sand injection pipes and water injection pipes on the steel sheet piles, and passes sand materials and water through the steel sheet piles during the normal pile pulling process. The sand injection pipe and the water pipe on the pile are injected at the same time, with the help of the strong vibration generated when the vibratory pile driver pulls out the pile, combined with the principle of sand and gravel vibration liquefaction, using the combination of water shock method and vibratory flushing method, water and sand are mixed and placed on the pile driver Under the action of strong vibration generated by pile pulling, the compaction effect can be achieved, so as to ensure the compactness of the holes after pile pulling, effectively inhibit the release of lateral earth pressure, and solve the problem of settlement and cracking caused by holes after pulling piles.

In the present invention, the raw materials for filling the holes after pile extraction are mainly sand and water stored separately. Compared with the processed mortar, it has advantages in cost and on-site storage. The ratio of sand and water in the use process is also avoided. The waste of resources caused by the amount of mortar configuration not meeting the construction requirements or affecting the progress of pile pulling operations.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a structural schematic diagram when the baffle plate blocks the discharge port when the control unit is a rotating shaft and a gear lever;

Fig. 3 is a structural schematic diagram when the discharge port is opened when the control unit is a rotating shaft and a gear lever;

Fig. 4 is a structural schematic diagram when the baffle plate blocks the discharge port when the control unit is a pull cord;

Fig. 5 is a structural schematic diagram when the discharge port is opened when the control unit is a pull rope;

Fig. 6 is a structural schematic diagram of the water injection pipe and the sand injection pipe being lower than the upper edge of the main steel plate;

Fig. 7 is the structural representation when mixing chamber is vertical pipeline;

Fig. 8 is a structural schematic diagram of a steel sheet pile in use;

Reference signs: 1, main steel plate, 101, main steel plate, 102, side steel plate, 2, water injection pipe, 3, sand injection pipe, 4, mixing chamber, 5, non-return assembly, 501, rotating part, 502, baffle plate , 503, gear lever, 504, rotating shaft, 505, guard plate, 507, pull rope, 6, discharge port, 7, dry sandblasting machine, 8, upper water pump, 9, vibratory pile driver.

Detailed ways

The technical solutions of the present invention will be further elaborated below in conjunction with the accompanying drawings and specific embodiments. The parts that are not described in detail and disclosed in the following embodiments of the present invention should be understood as prior art known or should be known to those skilled in the art .

As shown in FIG. 1 and FIG. 6 , the present invention discloses a steel sheet pile, which includes a main steel plate 1 and a sand injection pipe 3 and a water injection pipe 2 arranged on the inner surface of the main steel plate 1 .

The main steel plate 1 is elongated overall, with a trapezoidal cross-section, including a main steel plate 101 and side steel plates 102 oppositely arranged on both sides of the main steel plate 101 .

The sand injection pipe 3 and the water injection pipe 2 are both arranged in the groove of the main steel plate 1 and fixed on the main steel plate 101 . The sand injection pipe 3 and the water injection pipe 2 extend from top to bottom along the length direction of the main steel plate 1, and the lower ends of the sand injection pipe 3 and the water injection pipe 2 are connected with the mixing chamber 4, which has an outlet for water supply and sand mixing. The feed port 6 and the non-return assembly 5 capable of controlling the opening or closing of the discharge port 6.

The sand injection pipe 3 and the water injection pipe 2 are distributed in a V shape. The lower ends of the sand injection pipe 3 and the water injection pipe 2 meet at the feed inlet at the top of the mixing chamber 4, and the sand material in the sand injection pipe 3 and the water in the water injection pipe 2 can collide and mix at the feed inlet to increase the water and sand mixed effect.

The profile of the mixing chamber 4 is wedge-shaped with a large top and a small bottom. The side of the mixing chamber 4 opposite to the main steel plate 101 is an inclined plane, on which an outlet 6 is set, and an arc-shaped flow path is formed from the inlet to the outlet 6 . Water and sand flow into the flow channel through the feed port together, and then are discharged from the discharge port 6.

In addition, as shown in Figure 7, the mixing chamber 4 can also be set as a vertical pipe at the lower end of the sand injection pipe 3 and the water injection pipe 2, and the sand injection pipe 3 and the water injection pipe 2 all meet at the feed port of the vertical pipe, and the vertical A discharge port is provided at the lower end of the pipeline, and a non-return assembly 5 is provided at the discharge port.

The non-return assembly 5 includes a baffle 502 and a control unit capable of controlling the baffle 502 to open or close the discharge port 6 .

As shown in Figure 2 and Figure 3, the upper end of the baffle plate 502 is rotatably connected to the side wall of the mixing chamber 4 and is located above the discharge port 6. Specifically, the upper end of the baffle plate 502 is rotatably connected to the side wall of the mixing chamber 4 through the rotating member 501. Outside the side wall, the side wall forms a slope of the mixing chamber 4 facing away from the main steel plate 101 . The rotating part 501 is a rotating shaft, a hinge or a hinge, so that the baffle plate 502 can rotate around the rotating part 501, and it is sufficient to open or block the discharge port 6 . In this embodiment, the baffle plate 502 is connected to the mixing chamber 4 through hinges, and the specific installation method of the hinges is the prior art, and will not be repeated here.

The control unit includes a rotating shaft 504 and a gear lever 503 arranged on the rotating shaft 504. A torsion spring (not shown) is connected between the rotating shaft 504 and the gear lever 503. The gear lever 503 can move the baffle plate under the torsion of the torsion spring. 502 is blocked at the discharge port 6, and the impact force of the material discharged in the mixing chamber 4 can overcome the torsion force of the torsion spring and push the baffle plate 502 to move outward to open the discharge port 6. Specifically, a mounting seat is provided on the side wall of the mixing chamber, a through hole is provided at the lower end of the shift rod 503, and the rotating shaft 504 is supported on the mounting seat through the through hole of the shift rod, and a torsion spring is sleeved on the rotating shaft 504, and the torsion spring One end of it is fixed on the bar 503, and the other end is fixed on the side wall of the mixing chamber 4. During the piling process, the torsion force of the torsion spring drives the upper end of the gear rod 503 to be pressed against the baffle 502, and the discharge port 6 is blocked by the baffle 502 to prevent soil from entering the mixing chamber 4 from the discharge port 6 and causing the mixing chamber 4 1. The sand injection pipe 3 or the water injection pipe 2 is blocked. During the pile pulling process, by feeding the corresponding materials into the sand injection pipe 3 and the water injection pipe 2, the impact force of the materials discharged out overcomes the torsion force of the torsion spring to open the discharge port 6, To fill the material into the hole created by the pile pulling.

Still be provided with guard plate 505 on the sidewall of mixing chamber 4, guard plate 505 is positioned at the below of rotating shaft 504, and guard plate 505 can protect rotating shaft 504 and the torsion spring on it, gear rod 503 in the process of pile driving, reduces soil The impact of the layer on the torsion spring and the rotating shaft 504. During use, one end of the torsion spring can also be fixed on the shift rod 503 , and the other end can be fixed on the guard plate 505 .

As another arrangement of the non-return assembly 5, as shown in Figure 4 and Figure 5, the lower end of the baffle 502 is rotatably connected to the side wall of the mixing chamber 4 and located below the discharge port 6, and the control unit is connected to the baffle 502 inside the stay cord 507. Specifically, the lower end of the baffle plate 502 is connected to the side wall of the mixing chamber 4 through a rotating member 501, which is a hinge. It can be understood that the rotating member 501 can also be a rotating shaft or a hinge. The side of the baffle plate 502 facing the discharge port 6 is its inner side, and a stay rope 507 is fixed on the inner side of the baffle plate 502, and the stay rope 507 is a steel wire rope. The other end of the stay rope 507 stretches out from the mixing chamber 4 and then stretches out from the sand injection pipe 3 or the water injection pipe 2 and is fixed on the main steel plate 1 . The groove of the main steel plate 1 is provided with a fixed column (not shown) for fixing the stay rope 507, and the fixed column is arranged near the upper end of the sand injection pipe 3 and the water injection pipe 2, so as to prevent the fixed column from entering the soil during piling. layer.

By tightening the stay rope 507, the baffle plate 502 can block the discharge port 6. When the pile is pulled out, the stay cord 507 is loosened, and the material in the mixing chamber 4 impacts the baffle plate 502 to open the discharge port 6, thereby filling the material In the hole created by pulling the pile.

The length of the stay cord 507 is greater than the length of the main steel plate 1, so that after the stay cord 507 is loosened, the end of the stay cord 507 away from the baffle plate 502 can still be bound to the fixed column, preventing the stay cord 507 from falling into the sand injection pipe 3 or The water injection pipe 2 is inconvenient for later reuse.

As shown in FIG. 6 , both the sand inlet of the sand injection pipe 3 and the water inlet of the water injection pipe 2 are lower than the upper edge of the main steel plate 1 . It is convenient for the clamp of the steel sheet pile driver to hold the steel sheet pile.

The invention also discloses a construction method for preventing and controlling secondary diseases of steel sheet pile support, which includes the following steps:

S1: Connect the sand injection pipe 3 and the water injection pipe 2 of the steel sheet pile to the dry sand blasting machine 7 and the upper water pump 8 respectively;

S2: Lift the steel sheet pile upwards first, then start the dry sandblasting machine 7 and the water pump 8, sand and water enter the mixing chamber 4 for mixing, and the mixed sand and water mixture is vibrated and liquefied to be sprayed out through the lower outlet 6 , and fill in the hole after the steel sheet pile is pulled out;

Lift the steel sheet pile upwards by 20-40cm through the vibrating pile driver 9, first turn on the dry sandblasting machine 7 to supply air to the sand injection pipe 3, keep the wind pressure at 0.1-0.2MPa and send sand to the sand injection pipe 3, and then follow the water The pressure is 0.1MPa higher than the wind pressure, and the water-sand ratio is 0.8:1 for spraying; according to the geotechnical test, the bulk density of the selected sand is in the range of 1.36-1.60g/ ^cm3 , the porosity is between 42% and 47%, and the water injection volume It should be ensured that the injected dry sand is in a saturated state, and the water-sand ratio (volume ratio) is determined to be 0.8:1.

The pile pulling speed is determined according to different construction sites, and is generally controlled at 2cm/s~1.5cm/s. At this speed, it can ensure that the sand and water can fill the gaps after pile pulling in time, and at the same time make full use of the vibration effect of pile pulling to make The sand is dense.

S3: Use sand to compact the top of the hole after the steel sheet pile is pulled out.

The present invention takes the second-phase project of comprehensive improvement of Qianshan River in Zhuhai as an engineering example, and conducts construction research on the steel sheet piles of the Huayu Road sewage pipeline. The construction technology for the prevention and control of secondary disasters supported by steel sheet piles can effectively reduce the damage to the surrounding strata after the steel sheet piles are pulled out. After the construction is completed, the gaps removed by the steel sheet piles are backfilled densely, which greatly reduces the risk of road surface settlement, and the construction benefits are remarkable. The engineering practice has proved that this technology is operable and practical.

The specific construction process is as follows:

The construction process includes: construction preparation → measurement and setting out → application of sand-filled steel sheet piles → trench excavation, pipeline installation → trench backfilling construction → sand pouring and pile extraction → construction completion.

Construction preparation:

(1) Disclose the safety technology of the operators before construction, and clarify the operating procedures, division of labor, possible risk factors and protective measures taken during the operation.

(2) Before the construction, the pipelines in the construction area shall be detected by the combination of manual excavation trench and bottom-penetrating radar, and the buried conditions of underground pipelines in the construction area shall be found out.

(3) Reserve an appropriate amount of backfill coarse sand according to the volume of the soil hole to ensure the normal operation of the jetting machine.

(4) Post hazard notice boards on the operating site to warn the workers of the hazards and warn the surrounding unrelated personnel to stay away from the dangerous operating site.

(5) Determine the jet water-sand ratio

First, according to the geotechnical test, it is determined that the bulk density of the sand is in the range of 1.36-1.60g/ ^cm3 , and the porosity is between 42% and 47%. The amount of water injected should ensure that the injected dry sand is in a saturated state, and the water-sand ratio (volume ratio) is determined to be 0.8:1.

(6) Before the official construction, a trial spraying test should be carried out to determine the pile pulling speed, to ensure that the sand and water can fill the gaps after the pile pulling in time, and at the same time make full use of the vibration effect of the pile pulling to make the sand dense.

Measuring and setting out:

(1) Firstly, the permanent control points are verified, and the coordinate control network is established, and the accuracy should meet the requirements.

(2) Determine the trench axis strictly according to the construction drawing and well position coordinates, and then release the excavation line of the foundation trench according to the drawing design requirements.

(3) For the elevation control of the vertical section of the pipe ditch during construction, the elevation control piles are set at the base, the distance between the control piles is 10m, and the elevation is marked on the top of the piles.

Casting sand-type steel sheet piles

(1) Using the steel sheet pile of the present invention, the sand injection pipe 3 and the water injection pipe 2 are respectively φ4cm steel pipes, and the diameter of the discharge port 6 is 5cm. On the upper part of the steel sheet pile, the sand injection pipe 3 and the water injection pipe 2 are slightly lower than the upper edge of the steel sheet 1 of the main body so as to facilitate the clamping of the steel sheet pile machine. The two steel pipes are arranged in a V shape. At the bottom of the steel sheet pile, the two pipes intersect and pass into the wedge-shaped groove. The wedge-shaped groove is flush with the lower edge of the steel sheet pile.

(2) The steel sheet pile is driven by a vibratory pile driver 9 . Before piling, inspect the steel sheet piles one by one, remove the ordinary sheet piles with corrosion and serious deformation at the connection lock, and ensure that the entrance of the sand injection pipe and the water injection pipe are unobstructed, and the unqualified steel sheet piles can be used after being repaired. Apply grease to the lock of the steel sheet pile to facilitate driving in and out.

(3) The steel sheet piles are driven by the screen-type root-by-root driving method. The screen-type driving method is not easy to cause buckling, twisting, tilting and unevenness of the wall surface, and the driving precision is high, and it is easy to realize sealing and closing. During construction, insert 10 to 20 steel sheet piles into the guide frame in a row to make it screen-like, and then drive. Usually, a group of steel sheet piles at both ends of the screen wall are driven to the design elevation or a certain depth, and the verticality is strictly controlled. .

trench excavation

(1) The trench excavation adopts the step-back method and is divided into steps. During the excavation process, the construction principle of "grooving support, first supporting and then digging, layered excavation, and over-excavation is strictly prohibited" shall be followed. Excavation is carried out by a backhoe excavator. During the excavation, it strives to be excavated and transported. During the excavation process, it should cooperate with the support. The excavator must be supported in time after digging to prevent the wall from becoming unstable and causing the trench to collapse.

(2) Excavators and dump trucks are directed by special personnel to the designated location for construction. During the soil loading process, personnel within the working radius of dump trucks and excavators are strictly prohibited from approaching. Arrange special personnel to strengthen the supervision of dump trucks, strictly control them, and resolutely put an end to super-high and overloaded dump trucks.

(3) The pipeline is installed manually with a crane to hoist the pipeline into the trench. When hoisting, the contact between the steel wire rope and the cast iron pipe is separated by waste rubber pads to protect the cast iron pipe and the anti-corrosion layer. Pipeline installation is carried out from downstream to upstream, and the centerline and elevation of the pipeline are controlled. When installing the pipeline, install the socket along the direction of the water flow, and the socket against the direction of the water flow, and install them sequentially from the low point to the high point. The pipeline installation adopts manual adjustment.

Trench backfill construction

(1) After the pipeline passes the airtightness test, the groove should be backfilled in time. The backfill should be stone chips, and the backfill should be compacted in layers.

(2) Before backfilling, the construction waste, accumulated water, silt and sundries on the base should be cleaned up. The range of 0.5m from the top of the pipeline foundation to the top of the pipeline must be backfilled and compacted manually. The backfilling on both sides of the pipeline shall be carried out at the same time, and the height difference between the two sides shall not exceed 0.3m, and attention shall be paid to the compaction quality of the axillary corners of the pipeline.

(3) When backfilling the part above 500mm above the pipe top, mechanical backfilling, compaction or rolling can be used from both sides of the pipe axis at the same time.

Vibrating Pile Pulling While Filling Sand

(1) Coarse sand is used for spraying sand, and the sand should be protected from rain during transportation and storage to ensure that the sand is dry. It should be sieved before loading into the injection machine to prevent debris such as large stones from mixing into the nozzle to block the nozzle.

(2) After the pile pulling starts to lift 30cm, sand injection and water injection are started. At the beginning of spraying, the air should be supplied first, and then the machine should be turned on to inject sand and feed materials. Keep the wind pressure at 0.1-0.2MPa, the water pressure should be about 0.1MPa higher than the wind pressure, and spray according to the water-sand ratio of 0.8:1. The supply of material to the dry sandblasting machine should be continuous and even when spraying. When the machine is running normally, there should be enough stock in the dry sandblasting machine. When the spraying work is completed or the spraying is interrupted for some reason, the accumulated material in the sand injection pipe 3 should be cleaned up. When finished, the wind should be closed after the injection of the sand material in the sand injection pipe 3 is completed.

(3) When spraying sandy soil, irrigation should also be carried out at the same time. The dry sand left in the tank is mixed with water and discharged from the discharge port 6 under the action of high-pressure airflow, and the mixture is quickly filled in the holes in the steel sheet pile.

(5) In order to ensure that the steel sheet piles are pulled out by the jumping pile method, one pile is pulled out at intervals after the pile is pulled out. The jumping pile method can make the sand backfill more compact and effectively reduce the pullout of adjacent steel sheet piles. out the impact.

(6) The extracted steel sheet piles need to be cleaned for sand inlet pipes and water inlet pipes for easy turnover.

(7) Re-compact the sand on the top of the steel sheet pile.

Construction Notes

(1) The steel sheet piles are pulled out using the backward pulling method to avoid the impact of the heavy steel sheet pile foundation on the subgrade structure.

(2) When the excavator excavates the soil, lay the steel plate to increase the force-bearing area and reduce the disturbance to the trench foundation during the excavation process.

(3) During the spraying process, if there is a failure such as pipe blockage, wind power failure, etc., the water gate should be closed immediately, and the material pipe should be conveyed by tapping method when dealing with pipe blockage.

(4) The air inlet of the sandblasting machine is well sealed to prevent dust from being blown by air leakage. During the construction process, the exhaust gas will be discharged along the gaps between the steel sheet piles, and the gaps between the steel sheet piles are covered with safety nets to prevent sand from flying.

The present invention adopts the method of adding sand injection pipe 3 and water injection pipe 2 on the steel sheet pile, merging them together at the bottom of the steel sheet pile, and installing the anti-reverse assembly 5 to prevent the influx of soil when the steel sheet pile is driven. After the trench backfilling construction is completed , in the process of normal pile pulling, sand and water are simultaneously injected through the sand injection pipe 3 and water injection pipe 2 on the steel sheet pile of the present invention, and the water and sand are mixed and liquefied by vibration effect, thereby flowing into the leftover water of the steel sheet pile The gap, using the pile-jumping method to pull out the steel sheet pile construction, can effectively reduce the impact of the adjacent steel sheet pile pullout. void problem.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A steel sheet pile is characterized in that: it comprises a main body steel plate (1) and a sand injection pipe (3) and a water injection pipe (2) arranged on the inner surface of the main body steel plate (1), the sand injection pipe (3) and the water injection pipe (2) are arranged along the length direction of the main steel plate (1), the inner surface of the main steel plate (1) and its lower part are provided with a mixing chamber (4), the lower ends of the sand injection pipe (3) and the water injection pipe (2) are both It communicates with the mixing chamber (4), and the mixing chamber (4) has a discharge port (6) through which water is supplied and sand is mixed and discharged, and a non-return component (5) capable of controlling the opening or closing of the discharge port (6). 2. A steel sheet pile according to claim 1, characterized in that the anti-reverse component (5) includes a baffle (502) and a control unit capable of controlling the baffle (502) to open or close the discharge port (6) . 3. A steel sheet pile according to claim 2, characterized in that the upper end of the baffle (502) is rotatably connected to the side wall of the mixing chamber (4) and located above the discharge port (6), and the control unit includes a rotating shaft (504) and the gear lever (503) that is arranged on the rotating shaft (504), a torsion spring is connected between the rotating shaft (504) and the gear lever (503), and the gear lever (503) can block the gear under the torsional force of the torsion spring. The plate (502) is blocked at the discharge port (6), and the impact force of the material discharged in the mixing chamber (4) can overcome the torsion force of the torsion spring and push the baffle (502) to move outward to open the discharge port (6 ). 4. A steel sheet pile according to claim 2, characterized in that the lower end of the baffle (502) is rotatably connected to the side wall of the mixing chamber (4) and located below the discharge port (6), and the control unit is connected to Stay cord (507) in baffle plate (502) inner side, the end of stay cord (507) is fixed on the main body steel plate (1) after stretching out by sand injection pipe (3) or water injection pipe (2). 5. A steel sheet pile according to claim 1, characterized in that the mixing chamber (4) is wedge-shaped with a large top and a small bottom. 6. A steel sheet pile according to claim 1, characterized in that the sand injection pipes (3) and water injection pipes (2) are distributed in a V shape. 7. A steel sheet pile according to claim 1, characterized in that the sand inlet of the sand injection pipe (3) and the water inlet of the water injection pipe (2) are both lower than the upper edge of the main steel plate (1). 8. A steel sheet pile according to claim 1, characterized in that the cross-section of the main steel plate (1) is trapezoidal, including the main steel plate (101) and side steel plates ( 102), the sand injection pipe (3) and the water injection pipe (2) are all arranged on the main steel plate (101). 9. A construction method for preventing and controlling secondary diseases of steel sheet pile support based on the steel sheet pile according to claim 1, characterized in that it comprises the following steps, S1: connect the sand injection pipe (3) and the water injection pipe (2) of the steel sheet pile to the dry sandblasting machine (7) and the water pump (8) respectively; S2: Lift the steel sheet pile upwards first, then start the dry sandblasting machine (7) and the water pump (8), sand and water enter the mixing chamber (4) for mixing, and the mixed sand-water mixture is vibrated and liquefied to pass through the bottom The discharge port (6) sprays out and fills in the hole after the steel sheet pile is pulled out; S3: Use sand to compact the top of the hole after the steel sheet pile is pulled out. 10. The construction method for secondary damage prevention and control of steel sheet pile support for steel sheet piles according to claim 9, characterized in that, in step S2, after the steel sheet piles are lifted up by 20-40cm by the vibrating pile driver (9), first Turn on the dry sandblasting machine (7) to supply air to the sand injection pipe (3), keep the wind pressure at 0.1-0.2MPa and send sand to the sand injection pipe (3), and then according to the water pressure is 0.1MPa higher than the wind pressure, The water-sand ratio is 0.8:1 for spraying.