Reinforced concrete hollow slab pile with improved joint impermeability and construction method thereof

Abstract

The application discloses a reinforced concrete hollow slab pile capable of improving joint impermeability and a construction method thereof, which comprises a pile body and a pile tip located at the bottom of the pile body, a reserved groove is arranged in the pile body, a steel reinforcement cage which is matched with the structure of the reserved groove is arranged in the reserved groove, the opening at the top of the reserved groove is sealedly connected with the pile body through a pile cap with a lifting hook, a groove is arranged on one side edge of the pile body, a protruding block which is matched with the structure of the groove is arranged on the other side edge of the pile body, grouting holes which are located on the same side edge of the pile body are arranged at the two ends of the groove and the protruding block, the grouting holes are communicated with the outside of the pile body through clamping grooves, the cross section of the clamping grooves is T-shaped, and a steel plate which is matched with the structure of the clamping grooves is arranged in the clamping grooves. The reinforced concrete hollow slab pile capable of improving joint impermeability and the construction method thereof adopt the above structure, and solve the problem that the prior art cannot perform grouting reinforcement on the joint between adjacent slab piles under the static force pressing pile or hammer pressing pile process to improve the impermeability.

Description

Technical Field

[0001] This invention relates to the field of pile foundation engineering technology, and in particular to a reinforced concrete hollow sheet pile that can improve the impermeability of joints and its construction method. Background Technology

[0002] Reinforced concrete sheet piles are widely used in pile foundation engineering due to their advantages such as high strength, high rigidity, convenient material sourcing, and simple construction. They are suitable for deep foundation pits in cohesive soil, silt, and sand with sidewall safety levels of I, II, and III.

[0003] However, reinforced concrete sheet piles have some limitations in use. Firstly, their bearing capacity is fixed during design and construction. When the soil around the foundation pit deforms significantly or shows signs of collapse, the only solutions are to accelerate the construction of the foundation layer, increase its thickness, and add supports. The design of reinforced concrete sheet piles does not consider pre-planning for bearing redundancy to address potential hazards during construction. Secondly, during reinforced concrete sheet pile support, the joints between adjacent sheet piles become weak points prone to seepage failure due to the presence of gaps.

[0004] Chinese invention patent application No. 202211668205.8, entitled "A Precast Diaphragm Wall and Its Construction Method," discloses a precast diaphragm wall composed of sheet piles, trenches, and grouting pipes. This invention injects bonding grout into the bottom of the diaphragm wall through grouting pipes, ensuring the grout completely fills the gap between two sheet piles, thereby reducing water leakage. However, in actual construction, the above construction method has the following problems: After the diaphragm trench is excavated, to prevent trench wall collapse, the conventional practice is to use mud slurry to protect the trench wall. On the one hand, considering that the grouting pipe is fixed to the sheet piles, the mud slurry in the trench wall can cause blockage of the grouting pipe during the lowering of the sheet piles. On the other hand, the density of mud slurry in the conventional trench wall is similar to that of bonding grout, which is not conducive to the grouting process. Therefore, the feasibility of this technical solution is not strong. Furthermore, this technology is only applicable after a continuous trench has been pre-excavated using construction machinery before the sheet piles are lowered. Under static or hammer-driven pile driving processes, this technology cannot solve problems such as grout hole collapse and blockage, or difficulty in grouting, that occur during pile driving. Therefore, it is particularly necessary to develop a reinforced concrete sheet pile technology that can smoothly achieve grouting at the joints under static or hammer-driven pile driving construction processes. Summary of the Invention

[0005] The purpose of this invention is to provide a reinforced concrete hollow sheet pile and its construction method that can improve the impermeability of joints, solving the problem that existing technologies cannot perform grouting reinforcement at the joints of adjacent sheet piles to improve their impermeability under static pile driving or hammer pile driving processes.

[0006] To achieve the above objectives, the present invention provides a reinforced concrete hollow sheet pile that improves the impermeability of joints, comprising a pile body and a pile tip located at the bottom of the pile body. The pile body has a reserved groove, and a reinforcing cage adapted to its structure is provided in the reserved groove. The top opening of the reserved groove is sealed to the pile body through a pile cap with a hook. A groove is provided on one side of the pile body, and a protrusion adapted to the structure of the groove is provided on the other side of the pile body. Both ends of the groove and the protrusion are provided with grouting holes located on the same side of the pile body. The grouting holes are connected to the outside of the pile body through a slot. The slot has a T-shaped cross-section, and a steel plate adapted to its structure is provided in the slot.

[0007] Preferably, there are at least two reserved slots.

[0008] Preferably, the surface of the steel plate is coated with a friction-reducing agent.

[0009] Preferably, the length of the steel plate is greater than the longitudinal length of the pile.

[0010] A construction method for reinforced concrete hollow sheet piles that can improve the impermeability of joints includes the following steps:

[0011] Step 1: Based on the actual site conditions, determine the pile length, pile diameter, reserved groove size and pile position of the reinforced concrete hollow sheet piles. The factory prefabricates the reinforced concrete hollow sheet piles according to the design requirements. Before construction, the site is leveled, and the surveyors use a total station to set out the pile positions. The supervision unit should verify the pile position results, and the pile position deviation should meet the requirements of relevant national mandatory standards.

[0012] Step 2: The strength of the reinforced concrete hollow sheet piles should reach 100% before driving. Use the hoisting equipment to connect the hook and lift the reinforced concrete hollow sheet piles to the designated location. During the lifting process, ensure that the equipment is stable and that the deviation of the pile tip position from the design scheme meets the requirements of national standards.

[0013] Step 3: Use static pile driving or hammer pile driving machine to drive the reinforced concrete hollow sheet piles to the design elevation;

[0014] Step 4: Place grouting guide pipes in the grouting holes of adjacent sheet piles, and inject micro-expansion plugging grout. The distance between the grouting guide pipe and the bottom of the grouting hole should not exceed 500mm. Grouting can be terminated when the total amount of grouting reaches the design requirements or the grouting volume reaches more than 80% and the pressure reaches the design requirements.

[0015] Step 5: Before the micro-expansion sealing grout has initially set, use lifting equipment to slowly and sequentially pull out the steel plates;

[0016] Step 6: Excavate the foundation pit according to the design requirements. If the soil around the foundation pit deforms more and there is a tendency to collapse during the subsequent construction process, remove the pile cap and put the steel cage into the reserved trench and pour concrete to improve the bearing capacity of the sheet pile.

[0017] Preferably, the actual site conditions include the physical and mechanical parameters of the soil, construction loads, and the condition of surrounding buildings.

[0018] Therefore, the present invention provides a reinforced concrete hollow sheet pile with the above-mentioned structure that can improve the impermeability of joints, and its construction method, which has the following beneficial effects:

[0019] 1. This invention solves the problem that existing technologies cannot perform grouting reinforcement at the joints of adjacent sheet piles to improve their impermeability under static pile driving or hammer pile driving processes.

[0020] 2. By setting a pre-reserved groove, the present invention increases the cross-sectional dimensions and the moment of inertia of the cross-section without increasing the project cost, thereby improving the overturning resistance of the concrete sheet pile.

[0021] 3. It has the ability to increase the load-bearing redundancy of reinforced concrete hollow sheet piles. When there is a tendency for collapse around the foundation pit, the load-bearing capacity of the sheet piles can be increased by hoisting the steel cage and pouring concrete.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a top view of an embodiment of a reinforced concrete hollow sheet pile that can improve the impermeability of joints according to the present invention;

[0024] Figure 2 This is a cross-sectional schematic diagram of an embodiment of the present invention, which improves the impermeability of joints, after installation.

[0025] Figure 3 This is a schematic diagram of an embodiment of the lap joint state of a reinforced concrete hollow sheet pile that can improve the impermeability of the joint according to the present invention.

[0026] Figure 4 This is a schematic diagram of an embodiment of the present invention for hoisting a steel cage in a reinforced concrete hollow slab pile that can improve the impermeability of joints.

[0027] Figure Labels

[0028] 1. Pile body; 2. Pile tip; 3. Reserved groove; 4. Reinforcing cage; 5. Hook; 6. Pile cap; 7. Groove; 8. Protrusion; 9. Grouting hole; 10. Slot; 11. Steel plate; 12. Soil layer. Detailed Implementation

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] like Figure 1-4 As shown, a type of reinforced concrete hollow sheet pile that improves joint impermeability includes a pile body 1 and a pile tip 2 located at the bottom of the pile body 1. The pile tip 2 facilitates the use of static pile driving or a hammer pile driver to drive the reinforced concrete hollow sheet pile into the soil layer 12. The pile body 1 has pre-reserved slots 3, with at least two slots. Each pre-reserved slot 3 contains a reinforcing cage 4 adapted to its structure. The pre-reserved slot 3 provides a position for hoisting the reinforcing cage 4, facilitating the hoisting and pouring of concrete to improve the bearing capacity of the sheet pile should subsequent construction processes encounter situations where soil deformation around the foundation pit increases or there is a tendency for collapse. The top opening of the pre-reserved slot 3 is sealed to the pile body 1 via a pile cap 6 with a hook 5. The pile cap 6 prevents debris from falling into the pre-reserved slot 3 and affecting the subsequent hoisting of the reinforcing cage 4, while the hook 5 facilitates the overall movement of the reinforced concrete hollow sheet pile.

[0031] A groove 7 is provided on one side of the pile body 1, and a protrusion 8 adapted to the structure of the groove 7 is provided on the other side of the pile body 1. The cooperation of the groove 7 and the protrusion 8 can improve the stability of the connection when two pile bodies 1 are overlapped. Both ends of the groove 7 and the protrusion 8 are provided with grouting holes 9 located on the same side of the pile body 1. The grouting holes 9 are connected to the outside of the pile body 1 through a slot 10. The slot 10 has a T-shaped cross-section, and a steel plate 11 adapted to its structure is provided inside the slot 10. The steel plate 11 can effectively prevent the grouting holes 9 from collapsing and becoming blocked during the pile driving process. The length of the steel plate 11 is greater than the longitudinal length of the pile body 1. The length design of the steel plate 11 makes it convenient for the construction workers to pull out the steel plate 11 using lifting equipment before the micro-expansion sealing grout has initially set. The surface of the steel plate 11 is coated with a layer of friction reducing agent, which can facilitate the construction workers to pull out the steel plate 11 and reduce the frictional resistance when pulling out the steel plate 11.

[0032] A construction method for reinforced concrete hollow sheet piles that can improve the impermeability of joints includes the following steps:

[0033] Step 1: Based on the actual site conditions, determine the pile length, pile diameter, reserved groove size, and pile location of the reinforced concrete hollow sheet piles. The actual site conditions include the physical and mechanical parameters of the soil, construction loads, and the condition of surrounding buildings. The factory prefabricates the reinforced concrete hollow sheet piles according to the design requirements. Before construction, the site is leveled, and surveyors use a total station to lay out the pile locations. The supervision unit should verify the pile location results, and the pile location deviations should meet the requirements of relevant national mandatory standards.

[0034] Step 2: The strength of the reinforced concrete hollow sheet piles should reach 100% before driving. Use the hoisting equipment to connect the hook 5 to lift the reinforced concrete hollow sheet piles to the designated position. During the lifting process, ensure that the equipment is stable. The deviation between the position of the pile tip 2 and the design scheme should meet the requirements of national standards.

[0035] Step 3: Use static pile driving or hammer pile driving machine to drive the reinforced concrete hollow sheet piles to the design elevation.

[0036] Step 4: Place a grouting guide pipe in the grouting hole 9 of the adjacent sheet pile, and inject micro-expansion plugging grout. The distance between the grouting guide pipe and the bottom of the grouting hole 9 should not exceed 500mm. Grouting can be terminated when the total grouting volume reaches the design requirements or the grouting volume reaches more than 80% and the pressure reaches the design requirements.

[0037] Step 5: Before the micro-expansion sealing grout initially sets, use lifting equipment to slowly pull out the steel plates 11 one by one, so that the micro-expansion sealing grout in the grouting holes 9 of adjacent sheet piles solidifies together, thereby achieving grouting reinforcement at the joint of adjacent sheet piles to improve their impermeability.

[0038] Step 6: Excavate the foundation pit according to the design requirements. If the soil around the foundation pit deforms more and there is a tendency to collapse during the subsequent construction process, remove the pile cap 6 and put the steel cage 4 into the reserved groove 3 and pour concrete to improve the bearing capacity of the sheet pile.

[0039] Therefore, the present invention provides a reinforced concrete hollow sheet pile with improved joint impermeability and its construction method, which solves the problem that existing technologies cannot perform grouting reinforcement at the joints of adjacent sheet piles to improve their impermeability under static or hammer-driven pile driving processes. Without increasing project costs, it increases the cross-sectional dimensions, increases the moment of inertia of the cross-section, and improves the overturning resistance of the concrete sheet pile. It also has load-bearing redundancy, allowing for increased load-bearing capacity of the sheet pile by lowering a reinforcing cage and pouring concrete when there is a tendency for collapse around the foundation pit.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A construction method for reinforced concrete hollow sheet piles that can improve the impermeability of joints, characterized in that: The utility model relates to a reinforced concrete hollow slab pile which comprises a pile body and a pile tip at the bottom of the pile body, a reserved groove is arranged in the pile body, a steel cage is arranged in the reserved groove, the top opening of the reserved groove is connected with the pile body in a sealed mode through a pile cap with a lifting hook, a groove is arranged on one side edge of the pile body, a protrusion is arranged on the other side edge of the pile body and is matched with the structure of the groove, grouting holes are arranged at both ends of the groove and the protrusion and are located on the same side edge of the pile body, the grouting holes are communicated with the outside of the pile body through clamping grooves, the cross section of the clamping grooves is T-shaped, and a steel plate is arranged in the clamping grooves and is matched with the structure of the clamping grooves. The construction method comprises the following steps: Step 1: according to the actual situation on site, the length, diameter, size of the reserved groove and pile position of the reinforced concrete hollow slab pile are determined, the reinforced concrete hollow slab pile is prefabricated in the factory according to the design requirements, the site is leveled before construction, the pile position is determined by using a total station instrument, the pile position result is reviewed by the supervision unit, and the pile position deviation should meet the requirements of the relevant mandatory standards of the state; Step 2: the strength of the reinforced concrete hollow slab pile before driving should reach 100%, the reinforced concrete hollow slab pile is hoisted to the designated position by using hoisting equipment connected with the lifting hook, the equipment is ensured to be stable during hoisting, and the deviation of the position of the pile tip from the design scheme should meet the requirements of the national standards; Step 3: the reinforced concrete hollow slab pile is pressed to the design elevation by using a static pressure pile or a hammering pile press; Step 4: the grouting guide pipe is placed in the grouting hole of the adjacent slab pile, the micro-expansion leak-stopping grouting material is pressed and injected, the distance between the grouting guide pipe and the bottom of the grouting hole is not more than 500 mm, the grouting is terminated when the total grouting amount reaches the design requirement or the grouting amount reaches more than 80% and the pressure reaches the design requirement; Step 5: the steel plate is pulled out in sequence and slowly by using the hoisting equipment before the micro-expansion leak-stopping grouting material is initially cured; Step 6: the foundation pit is excavated according to the design requirements, and when the surrounding soil of the foundation pit is deformed and increased, and has a tendency of collapse in the subsequent construction process, the pile cap is removed, the steel cage is hoisted and placed in the reserved groove, and the concrete is poured to improve the bearing capacity of the slab pile.

2. The construction method of a reinforced concrete hollow slab pile with improved joint impermeability according to claim 1, characterized in that: The number of the reserved grooves is at least two.

3. The construction method of a reinforced concrete hollow slab pile with improved joint impermeability according to claim 2, characterized in that: A layer of friction-reducing agent is coated on the surface of the steel plate.

4. The construction method of a reinforced concrete hollow slab pile with improved joint impermeability according to claim 3, characterized in that: The length of the steel plate is greater than the longitudinal length of the pile body.

5. The construction method of a reinforced concrete hollow slab pile with improved joint impermeability according to claim 1, characterized in that: The actual situation on site includes the physical and mechanical parameters of the soil quality on site, the construction load and the surrounding buildings.

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