A construction treatment method for burying a stuck hammer after a punching long pile gets stuck

Abstract

A construction treatment method for burying a stuck hammer after punching a long pile. The construction treatment steps are as follows: (1) Confirm the characteristic value of the design bearing capacity of the pile foundation and the safety factor, review and judge whether the bearing capacity requirements of the pile foundation can be met through post-grouting of the pile foundation; (2) When the bearing capacity requirements of the pile foundation are met through post-grouting of the pile foundation, abandon fishing for the original punching hammer and backfill the original pile with riprap; (3) Reorganize the punching construction with a new punching hammer. When the punching hammer reaches the top of the old punching hammer and cannot continue to punch down, stop punching and conduct mud circulation to clean the hole; (4) Install the steel reinforcement cage and conduct secondary hole cleaning; (5) After the mud specific gravity, sand content, and pile bottom sediment all meet the design requirements, pour underwater concrete; (6) After the concrete reaches the design strength, drill grouting holes in the concrete; (7) Use cement slurry or glass water to conduct high-pressure grouting at the pile bottom. This treatment method is to continue construction without changing the pile position when the hammer is stuck, without delaying the construction period and reducing the construction cost.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation construction, and specifically to a construction treatment method for burying a hammer after a long punching pile gets stuck with a hammer. Background Technique

[0002] In the punching construction of bridge pile foundations, if geological conditions such as inclined rocks, boulders, interlayers, and karst caves are encountered during the drilling process and the stroke is not well controlled, it is very easy to cause a hammer jamming accident. Currently, there are two common methods for dealing with a jammed hammer: one is to try to pull the punching hammer obliquely at different angles. If the steel wire rope is broken, divers still need to be sent to the bottom of the pile to tie the steel wire rope, which has great potential safety hazards; the other is to abandon fishing for the punching hammer, backfill the soil, change the pile position, and re-punch. The above treatments have a relatively long construction period, high costs, and great potential safety hazards. Since the hammer burying accident occurs deep underground and is "invisible and intangible", it makes the accident treatment very difficult. Many construction units, due to lack of treatment experience, have tried their best to fish for it, but still ended in failure.

[0003] If the hammer head cannot be taken out, losing a pile hammer not only results in the cost of the pile hammer, but often also causes the abandonment of the pile position, requiring additional piles to be driven, delaying the construction period, and causing double losses of the construction period and investment to the construction unit. Summary of the Invention

[0004] The purpose of the present invention is to provide a construction treatment method for burying a hammer after a long punching pile gets stuck with a hammer. This construction treatment method for burying a hammer after a long punching pile gets stuck with a hammer is to continue construction without changing the pile position when the hammer head cannot be taken out, without delaying the construction period and reducing construction costs.

[0005] In order to achieve the purpose of the present invention, the technical solution adopted is as follows:

[0006] A construction treatment method for burying a hammer after a long punching pile gets stuck with a hammer, characterized in that the construction treatment includes the following steps:

[0007] (1) According to the design specifications, confirm the characteristic value of the design bearing capacity of the pile foundation and the safety factor, review and judge whether the pile foundation bearing capacity requirements can be met through post-grouting of the pile foundation. The ultimate value of the pile foundation bearing capacity is: , due to the reason of the hammer jamming, the pile length fails to be constructed according to the original design. According to the principle of post-grouting reinforcement of the pile foundation , through the correction of βs and βp, to achieve meeting the pile foundation bearing capacity;

[0008]

[0009]

[0010]

[0011] 。

[0012] (2) When the bearing capacity of the pile foundation meets the requirements through post-grouting of the pile foundation, abandon salvaging the original impact hammer, backfill the original pile with crushed stones, requiring that the particle size of the crushed stones is less than 15 cm, and the backfill height is more than 3 m above the position where the hammer is stuck.

[0013] (3) Reorganize the punching construction with a new impact hammer. When the impact hammer reaches the top of the old impact hammer and cannot continue to punch down, stop punching, so that the crushed stones fill and compact the bottom of the pile foundation to avoid settlement, and then carry out mud circulation for hole cleaning.

[0014] (4) After the hole cleaning meets the construction requirements, install the steel reinforcement cage and then carry out secondary hole cleaning.

[0015] (5) When the mud specific gravity, sand content, and sediment at the bottom of the pile all meet the design requirements, pour underwater concrete.

[0016] (6) After the concrete reaches the design strength, drill holes in the concrete, requiring that the drilling depth is greater than the length of the concrete.

[0017] (7) Carry out high-pressure grouting at the bottom of the pile with cement slurry or glass water. When the high-pressure grouting and curing meet the requirements, the construction treatment is completed.

[0018] Further preferably: The drilling of the concrete is to drill three grouting holes from the top to the bottom of the concrete pile foundation, and the three grouting holes are evenly distributed around the center of the concrete pile foundation.

[0019] The construction treatment method for burying the hammer after the impact hammer is stuck in the long punching pile is that when the impact hammer is stuck during the construction process and the hammer head cannot be taken out, confirm the characteristic value of the bearing capacity and the safety factor of the pile foundation design, review and judge whether the bearing capacity requirements of the pile foundation can be met through post-grouting of the pile foundation. When the bearing capacity of the pile foundation meets the requirements through post-grouting of the pile foundation, abandon salvaging the original impact hammer, backfill the original pile with crushed stones, requiring that the particle size of the crushed stones is less than 15 cm, and the backfill height is more than 3 m above the position where the hammer is stuck. Reorganize the punching construction with a new impact hammer. When the impact hammer reaches the top of the old impact hammer and cannot continue to punch down, stop punching, carry out mud circulation for hole cleaning. After the hole cleaning meets the construction requirements, install the steel reinforcement cage and then carry out secondary hole cleaning. When the mud specific gravity, sand content, and sediment at the bottom of the pile all meet the design requirements, pour underwater concrete. After the concrete reaches the design strength, carry out high-pressure grouting by drilling holes in the concrete to achieve the purpose of meeting the bearing capacity of the pile foundation, realizing continuous construction without changing the pile position, without delaying the construction period, reducing the construction cost, and also avoiding safety accidents during the salvage of the stuck hammer. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the pile foundation concrete after the construction treatment of burying the hammer after the impact hammer is stuck in the long punching pile;

[0021] Figure 2 It is a schematic diagram of the arrangement of grouting holes;

[0022] Figure 3 It is a schematic diagram of the pile foundation when the hammer is stuck;

[0023] Figure 4 It is a schematic diagram of backfilling crushed stones into the pile foundation;

[0024] The names corresponding to the serial numbers in the figure are:

[0025] 1. Original impact hammer, 2. Steel wire rope, 3. Steel casing, 4. Crushed stones, 5. Concrete, 6. Grouting body, 7. Grouting hole. Specific implementation manners

[0026] In order to make the technical solutions and advantages of this application clearer, the following combines examples to clearly and completely describe this technical solution.

[0027] Example 1

[0028] Adopt the following steps to complete the construction treatment of burying the hammer after the impact long pile is stuck:

[0029] (1) According to the design specifications, confirm the characteristic value of the bearing capacity of the pile foundation and the safety factor, review and judge whether the bearing capacity requirements of the pile foundation can be met through post-grouting of the pile foundation.

[0030] (2) When the bearing capacity requirements of the pile foundation are met through post-grouting of the pile foundation, after the steel wire rope 2 connected to the original impact hammer 1 is broken, abandon fishing for the original impact hammer 1, and backfill the original pile with crushed stones 4. It is required that the particle size of the crushed stones 4 is less than 15 cm, and the backfill is more than 3 m higher than the position where the hammer is stuck.

[0031] (3) Use a new impact hammer to reorganize the impact hole construction. When the impact hammer reaches the top of the old impact hammer and cannot continue to impact downward, stop the impact hole and conduct mud circulation to clean the hole.

[0032] (4) After the hole cleaning meets the construction requirements, install the steel reinforcement cage in the middle of the steel casing 3, and then conduct secondary hole cleaning.

[0033] (5) After the mud specific gravity, sand content, and pile bottom sediment all meet the design requirements, pour underwater concrete 5.

[0034] (6) After the concrete reaches the design strength, drill holes in the concrete. It is required that the drilling depth is greater than the length of the concrete. The drilling of the concrete is to drill three grouting holes 7 from the top to the bottom of the concrete pile foundation, and the three grouting holes are evenly distributed around the center of the concrete pile foundation.

[0035] (7) Use cement slurry or glass water to conduct high-pressure grouting at the pile bottom to fill the bottom of the concrete pile foundation with the grouting body 6. When the high-pressure grouting and curing reach the requirements, the construction treatment is completed.

[0036] Construction application cases

[0037] The pile type of the No. 5 pile foundation of a certain bridge is a friction pile. The designed pile length is 37m, the pile diameter is Φ2.2m, the original designed pile top elevation is 520.5m, and the pile bottom elevation is 483.5m. During the punching process, the drill got stuck at the position where the elevation was 481.5m, and the measured net hole depth at this time was 34m. The formation at the stuck drill position is strongly weathered siltstone. The project adopted the method of pulling obliquely and lifting obliquely. The drilling rig was moved in the opposite direction of the lifting rope azimuth of the accident drill bit to offset a certain distance, so that the drill bit lifting rope was in an inclined pulling state. After fixing the drilling rig, the winch was started to repeatedly lift the drill bit. After a period of time (10 - 20 minutes), the drilling rig was moved to another direction, and so on until the accident drill bit was pulled. However, the drill bit could not be taken out using this method. After several attempts, the steel wire rope of the drill bit broke, and the ground pile driver lost contact with the drill bit at the bottom of the hole. After project discussion, the post-buried hammer construction treatment method for the stuck hammer of the long punching pile in this application was adopted. The old punching hammer was abandoned, the original pile was backfilled with crushed stones, and the new punching hammer was used to continue punching until reaching the top of the old hammer. Then, the punching was stopped, the mud was circulated for hole cleaning, and underwater concrete was poured. After reaching the strength, concrete core drilling and post-grouting were carried out to increase the characteristic value of the single-pile bearing capacity of the pile foundation, meeting the construction and design requirements.

[0038] The above description is not a limitation to this application, and this application is not limited to the above examples. Any changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of this application shall fall within the protection scope of this application.

Claims

1. A construction treatment method for post-burying a stuck hammer in a long punched pile, characterized in that: The construction treatment includes the following steps: (1) According to the design specifications, confirm the characteristic value of the bearing capacity of the pile foundation and the safety factor, review and judge whether the bearing capacity requirements of the pile foundation can be met through post-grouting of the pile foundation; (2) When the bearing capacity requirements of the pile foundation are met through post-grouting of the pile foundation, abandon fishing for the original punching hammer, backfill the original pile with crushed stones, requiring that the particle size of the crushed stones is less than 15 cm, and the backfill is more than 3 m higher than the position where the hammer is stuck; (3) Use a new punching hammer to reorganize the punching construction. When the punching hammer reaches the top of the old punching hammer and cannot continue to punch down, stop punching and carry out mud circulation for hole cleaning; (4) After the hole cleaning meets the construction requirements, install the steel reinforcement cage and then carry out secondary hole cleaning; (5) After the mud specific gravity, sand content, and sediment at the bottom of the pile all meet the design requirements, pour underwater concrete; (6) After the concrete reaches the design strength, drill holes in the concrete, requiring that the drilling depth is greater than the length of the concrete; (7) Use cement slurry or glass water to carry out high-pressure grouting at the bottom of the pile. When the high-pressure grouting and curing meet the requirements, the construction treatment is completed.

2. The construction treatment method for post-burying a stuck hammer in a long punched pile according to claim 1, characterized in that: For the drilling of the concrete, three grouting holes are drilled from the top to the bottom of the concrete pile foundation, and the three grouting holes are evenly distributed around the center of the concrete pile foundation.

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