Underwater cast-in-place pile construction method for improving foundation bearing capacity of water conservancy project

Abstract

The invention relates to an underwater cast-in-place pile construction method for improving the foundation bearing capacity of a water conservancy project, and belongs to the technical field of water conservancy project foundation construction. S2, pile casing burying; s3, drilling to form a hole; s4, hole cleaning and checking; s5, a reinforcement cage is manufactured and installed; s6, guide pipe installation and concrete pouring; and S7, the sleeve is drawn, and the pile forming quality is checked. According to the underwater cast-in-place pile construction method for improving the bearing capacity of the foundation of the water conservancy project, construction is conducted through the underwater cast-in-place pile construction method, the compactness of a foundation soil layer and a pile body can be remarkably improved, and therefore the stability and the bearing capacity of the foundation of the water conservancy project are effectively improved; the foundation settlement problem of the water conservancy project is effectively controlled through the supporting effect of the pile bodies; through reasonable pile length and pile diameter design, it can be ensured that the pile body can bear enough external load in the vertical direction, and therefore the stability and safety of a foundation are kept.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy project foundation construction, in particular to an underwater cast-in-place pile construction method for improving the bearing capacity of a water conservancy project foundation. Background Art

[0002] In water conservancy projects, the bearing capacity of the foundation is crucial. In order to ensure the stability and safety of water conservancy projects, effective methods need to be adopted to improve the bearing capacity of the foundation. Underwater cast-in-place piles, as an advanced foundation treatment technology, have been widely used in water conservancy projects in recent years.

[0003] Underwater cast-in-place piles are a type of pile foundation formed by drilling holes underwater and pouring concrete. This construction method can make full use of the geological conditions underwater and directly pour concrete into the drilled holes to form a solid pile body. Compared with traditional foundation treatment methods, underwater cast-in-place piles have the advantages of convenient construction, strong adaptability, and high bearing capacity.

[0004] In water conservancy projects, the foundations often face complex geological conditions, such as soft soil, silt, sand, rock, etc. These geological conditions place high demands on the bearing capacity of the foundation. Traditional foundation treatment methods, such as excavation replacement method and heavy hammer compaction method, can improve the bearing capacity of the foundation to a certain extent, but they often have problems such as difficulty in construction, high cost, and limited effect.

[0005] With the continuous development of water conservancy engineering technology, the construction method of underwater bored piles is also constantly improving and perfecting. As an advanced foundation treatment technology, underwater bored piles have broad application prospects in water conservancy projects. By continuously improving and perfecting the construction method, its construction efficiency and quality can be further improved, providing a strong guarantee for the safety and stability of water conservancy projects. Therefore, this application proposes a construction method of underwater bored piles for improving the bearing capacity of the foundation of water conservancy projects to achieve the above purpose. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides an underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project, which has the advantages of high bearing capacity, environmental protection and energy saving, and solves the problems of inconvenient construction, poor adaptability and poor bearing capacity of the traditional underwater bored pile construction method.

[0007] To achieve the above object, the present invention provides the following technical solution: an underwater bored pile construction method for improving the bearing capacity of a water conservancy project foundation, comprising the following steps:

[0008] S1. Construction preparation: Select appropriate drilling rigs and drilling tools, arrange the construction site, and then measure and locate according to the design drawings to ensure the accuracy and precision of the pile position;

[0009] S2. Casing burial: First, make the casing required for construction according to the design drawings. After the casing is made, bury it underground to ensure the verticality and stability of the casing;

[0010] S3. Drilling: Install and position the drilling machine to ensure that the foundation for the drilling machine is stable; prepare the drilling mud and determine the mud consistency according to the drilling method and the formation conditions; start the drilling machine to carry out drilling operations, pay close attention to the changes in each soil layer, and adjust the construction footage and mud density in time;

[0011] S4. Hole cleaning and inspection: When the drilling reaches the required depth, the bottom of the hole should be cleaned immediately. After the hole is cleaned, the depth, diameter, position and hole shape of the hole should be checked to ensure that they meet the design requirements.

[0012] S5. Fabrication and installation of steel cage: In a flat processing area, fabricate the steel cage according to the design requirements of the drawings; vertically hang the fabricated steel cage into the hole and fix it after positioning;

[0013] S6. Conduit installation and concrete pouring: Use appropriate conduits for installation, connect the conduits firmly with threads, and add sealing rings; use the conduit method for underwater concrete pouring;

[0014] S7. Pulling out the casing and checking the quality of piles: For the full casing construction method, it is necessary to pull out the casing after pouring concrete; check the quality of the piles, including the integrity of the pile body, bearing capacity and pile top elevation.

[0015] Furthermore, the drilling rig and drilling tools in S1 need to meet the geological conditions of the construction site, and auxiliary equipment compatible with the drilling rig and drilling tools also needs to be prepared.

[0016] Furthermore, the site layout in S1 needs to ensure that the drilling rig can be stably installed and operated. For foundations with soft strata or slopes, reinforcement treatment is required.

[0017] Furthermore, the casing in S2 should be durable and watertight; the main functions of the casing in S2 are to prevent the hole wall from collapsing, isolate surface water, protect the ground at the hole mouth, and fix the pile hole position and drill bit guide.

[0018] Furthermore, the drilling machine in S3 needs to be installed and positioned so that the lifting pulley, the drill bit or the clamping hole of the fixed drill rod and the center of the casing are on the same vertical line to ensure the verticality of the drilling machine.

[0019] Furthermore, the mud in S3 has the functions of suspending drill cuttings, cooling the drill bit, lubricating the drill tool, increasing the hydrostatic pressure and preventing hole collapse; during the drilling process, it is necessary to continuously add mud and extract cuttings, and the verticality and aperture quality of the hole should also be checked regularly.

[0020] Furthermore, the purpose of the hole cleaning in S4 is to remove the sediment and mud at the bottom of the hole to ensure that the bottom of the hole is clean and flat; the hole cleaning method in S4 can select a positive circulation rotary drilling rig, a reverse circulation rotary machine vacuum mud suction machine and a slag suction barrel according to actual conditions.

[0021] Furthermore, the main bars of the steel cage in S5 are welded by lap joints, the reinforcing stirrups are connected by double-sided lap welding or connectors, and the spiral bars and main bars are connected by arc spot welding; during the installation of the steel cage, it should be prevented from twisting, deformation and floating.

[0022] Furthermore, a water sealing test should be carried out before the installation of the conduit in S6 to ensure that the conduit is leak-proof. When installing the conduit, the position of the crane hook should be adjusted so that the conduit is placed in the middle of the hole as much as possible, and the conduit should be lowered slowly to avoid collision with the steel cage. Before pouring the concrete in S6, the thickness of the sediment at the bottom of the hole should be measured. If the sediment thickness exceeds the specified standard, the hole should be cleaned for the second time, and the concrete pouring must be carried out continuously to prevent broken piles. During the pouring process, the slump and pouring speed of the concrete should be strictly controlled to ensure the quality of the concrete.

[0023] Furthermore, the pulling of the casing in S7 should be performed slowly to avoid affecting the quality of the pile.

[0024] Compared with the prior art, the present invention provides an underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project, which has the following beneficial effects:

[0025] 1. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project can significantly improve the compactness of the foundation soil layer and the pile body by adopting the underwater bored pile construction method, thereby effectively improving the stability and bearing capacity of the foundation of the water conservancy project; by utilizing the supporting effect of the pile body, the foundation settlement problem of the water conservancy project can be effectively controlled; through reasonable pile length and pile diameter design, it can be ensured that the pile body can withstand sufficient external load in the vertical direction, thereby maintaining the stability and safety of the foundation, and achieving the advantage of high foundation bearing capacity.

[0026] 2. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project can ensure the construction quality and efficiency of the bored piles by adopting the underwater bored pile construction method; through scientific construction procedures and strict quality control measures, the quality and stability of the pile body can be ensured, while reducing errors and waste in the construction process; by reducing material waste and energy consumption, the construction cost can be reduced, while reducing the impact on the environment, achieving the advantages of environmental protection and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a construction flow chart of an underwater bored pile construction method for improving the bearing capacity of a water conservancy project foundation. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project in this embodiment comprises the following steps:

[0030] S1. Construction preparation: Select appropriate drilling rigs and drilling tools, arrange the construction site, and then measure and locate according to the design drawings to ensure the accuracy and precision of the pile position;

[0031] S2. Casing burial: First, make the casing required for construction according to the design drawings. After the casing is made, bury it underground to ensure the verticality and stability of the casing;

[0032] S3. Drilling: Install and position the drilling machine to ensure that the foundation for the drilling machine is stable; prepare the drilling mud and determine the mud consistency according to the drilling method and the formation conditions; start the drilling machine to carry out drilling operations, pay close attention to the changes in each soil layer, and adjust the construction footage and mud density in time;

[0033] S4. Hole cleaning and inspection: When the drilling reaches the required depth, the bottom of the hole should be cleaned immediately. After the hole is cleaned, the depth, diameter, position and hole shape of the hole should be checked to ensure that they meet the design requirements.

[0034] S5. Fabrication and installation of steel cage: In a flat processing area, fabricate the steel cage according to the design requirements of the drawings; vertically hang the fabricated steel cage into the hole and fix it after positioning;

[0035] S6. Conduit installation and concrete pouring: Use appropriate conduits for installation, connect the conduits firmly with threads, and add sealing rings; use the conduit method for underwater concrete pouring;

[0036] S7. Pulling out the casing and checking the quality of piles: For the full casing construction method, it is necessary to pull out the casing after pouring concrete; check the quality of the piles, including the integrity of the pile body, bearing capacity and pile top elevation.

[0037] In this embodiment, the drilling rig and drilling tools in S1 need to meet the geological conditions of the construction site. At the same time, auxiliary equipment compatible with the drilling rig and drilling tools also needs to be prepared.

[0038] In this embodiment, the site layout in S1 needs to ensure that the drilling rig can be stably installed and operated. For foundations with soft strata or slopes, reinforcement treatment is required.

[0039] In this embodiment, the casing in S2 should be durable and watertight; the main functions of the casing in S2 are to prevent the hole wall from collapsing, isolate surface water, protect the ground at the hole mouth, and fix the pile hole position and drill bit guide.

[0040] In this embodiment, the drilling machine in S3 needs to be installed and positioned so that the lifting pulley, the drill bit or the clamping hole of the fixed drill rod and the center of the casing are on the same vertical line to ensure the verticality of the drilling machine.

[0041] In this embodiment, the mud in S3 has the functions of suspending drill cuttings, cooling the drill bit, lubricating the drill tool, increasing the hydrostatic pressure and preventing hole collapse; during the drilling process, it is necessary to continuously add mud and extract cuttings, and the verticality and aperture quality of the hole should be checked regularly.

[0042] In this embodiment, the purpose of hole cleaning in S4 is to remove sediment and mud at the bottom of the hole to ensure that the bottom of the hole is clean and flat; the hole cleaning method in S4 can select a positive circulation rotary drilling rig, a reverse circulation rotary machine vacuum mud suction machine and a slag suction barrel according to actual conditions.

[0043] In this embodiment, the main reinforcement of the steel cage in S5 is welded by lap welding, the reinforcing stirrups are connected by double-sided lap welding or connectors, and the spiral reinforcement and the main reinforcement are connected by arc spot welding; during the installation of the steel cage, it should be prevented from twisting, deformation and floating.

[0044] In this embodiment, a water sealing test should be carried out before the installation of the conduit in S6 to ensure that the conduit is leak-proof. When installing the conduit, the position of the crane hook is adjusted to place the conduit in the middle of the hole as much as possible, and the conduit is lowered slowly to avoid colliding with the steel cage. Before pouring concrete in S6, the thickness of the sediment at the bottom of the hole needs to be measured. If the sediment thickness exceeds the specified standard, the hole should be cleaned for the second time. The concrete pouring must be carried out continuously to prevent broken piles. During the pouring process, the slump and pouring speed of the concrete must be strictly controlled to ensure the quality of the concrete.

[0045] In this embodiment, the sleeve should be pulled out slowly in S7 to avoid affecting the quality of pile formation.

[0046] The beneficial effects of the present invention are:

[0047] The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project can significantly improve the compactness of the foundation soil layer and the pile body by adopting the underwater bored pile construction method, thereby effectively improving the stability and bearing capacity of the foundation of the water conservancy project; by utilizing the supporting effect of the pile body, the foundation settlement problem of the water conservancy project can be effectively controlled; by reasonably designing the pile length and pile diameter, it can be ensured that the pile body can withstand sufficient external load in the vertical direction, thereby maintaining the stability and safety of the foundation, and achieving the advantage of high foundation bearing capacity.

[0048] The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project can ensure the construction quality and efficiency of the bored piles by adopting the underwater bored pile construction method; can ensure the quality and stability of the pile body by a scientific construction process and strict quality control measures, while reducing errors and waste in the construction process; can reduce construction costs by reducing material waste and energy consumption, while reducing the impact on the environment, thereby achieving the advantages of environmental protection and energy saving.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An underwater bored pile construction method for improving the bearing capacity of a water conservancy project foundation, characterized in that: The following steps are involved: S1. Construction preparation: Select appropriate drilling rigs and drilling tools, arrange the construction site, and then measure and locate according to the design drawings to ensure the accuracy and precision of the pile position; S2. Casing burial: First, make the casing required for construction according to the design drawings. After the casing is made, bury it underground to ensure the verticality and stability of the casing; S3. Drilling: Install and position the drilling machine to ensure that the foundation for the drilling machine is stable; Prepare drilling mud and determine the mud consistency according to the drilling method and formation conditions; start the drilling rig to carry out drilling operations, pay close attention to the changes in each soil layer, and adjust the construction footage and mud density in a timely manner; S4. Hole cleaning and inspection: When the drilling reaches the required depth, the bottom of the hole should be cleaned immediately. After the hole is cleaned, the depth, diameter, position and hole shape of the hole should be checked to ensure that they meet the design requirements. S5. Fabrication and installation of steel cage: In a flat processing area, fabricate the steel cage according to the design requirements of the drawings; vertically hang the fabricated steel cage into the hole and fix it after positioning; S6. Conduit installation and concrete pouring: Use appropriate conduits for installation, connect the conduits firmly with threads, and add sealing rings; use the conduit method for underwater concrete pouring; S7. Pulling out the casing and checking the quality of piles: For the full casing construction method, it is necessary to pull out the casing after pouring concrete; check the quality of the piles, including the integrity of the pile body, bearing capacity and pile top elevation.

2. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1 is characterized in that: The drilling rig and drilling tools in S1 must meet the geological conditions of the construction site. At the same time, auxiliary equipment compatible with the drilling rig and drilling tools must also be prepared.

3. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1 is characterized in that: The site layout in S1 needs to ensure that the drilling rig can be stably installed and operated. For soft or sloping foundations, reinforcement treatment is required.

4. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The casing in S2 should be strong, durable and watertight; the main functions of the casing in S2 are to prevent the hole wall from collapsing, isolate surface water, protect the ground at the hole mouth, and fix the pile hole position and drill bit guide.

5. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The drilling machine in S3 is installed and positioned so that the lifting pulley, the drill bit or the clamping hole of the fixed drill rod and the center of the casing are on a vertical line to ensure the verticality of the drilling machine.

6. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The mud in S3 has the functions of suspending drill cuttings, cooling the drill bit, lubricating the drill tool, increasing the hydrostatic pressure and preventing hole collapse; during the drilling process, it is necessary to continuously add mud and extract cuttings, and the verticality and aperture quality of the hole should also be checked regularly.

7. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The purpose of the hole cleaning in S4 is to remove the sediment and mud at the bottom of the hole to ensure that the bottom of the hole is clean and flat; the hole cleaning method in S4 can select a positive circulation rotary drilling rig, a reverse circulation rotary machine vacuum mud suction machine and a slag suction barrel according to actual conditions.

8. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The main reinforcement of the steel cage in S5 is welded by lap joint, the reinforcing stirrups are connected by double-sided lap welding or connectors, and the spiral reinforcement and the main reinforcement are connected by arc spot welding; during the installation of the steel cage, it should be prevented from twisting, deformation and floating.

9. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: Before installing the conduit in S6, a water sealing test should be conducted to ensure that the conduit does not leak. When installing the conduit, adjust the position of the crane hook so that the conduit is placed in the middle of the hole as much as possible, and slowly lower the conduit to avoid collision with the steel cage. Before pouring concrete in S6, the thickness of the bottom ballast of the hole needs to be measured. If the thickness of the ballast exceeds the specified standard, the hole should be cleaned for the second time. Concrete pouring must be carried out continuously to prevent broken piles. During the pouring process, the slump and pouring speed of concrete must be strictly controlled to ensure the quality of concrete.

10. The underwater bored pile construction method for improving the bearing capacity of the foundation of a water conservancy project according to claim 1, characterized in that: The pulling of the casing in S7 should be done slowly to avoid affecting the quality of the pile.

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