Outward-extending anti-buoyancy anchor construction device and expanded diameter high-pressure jet grouting anti-buoyancy pile

Abstract

This invention discloses an outward-extending anti-buoyancy anchor construction device and an expanded-diameter high-pressure jet grouting anti-buoyancy pile, relating to the foundation field. The aim is to increase the maximum tensile force that the anti-buoyancy anchor can withstand and improve the pile quality of the anti-buoyancy pile. The technical solution adopted is as follows: The outward-extending anti-buoyancy anchor construction device includes a pile head, a casing, and anti-buoyancy reinforcement. The pile head is threadedly connected to the casing, and the anti-buoyancy reinforcement is located inside the casing. The lower end of the anti-buoyancy reinforcement is connected to the pile head. A flip-and-embed component is fixed to the outer periphery of the anti-buoyancy reinforcement, and the flip-and-embed component includes a fixed reinforcement and a movable reinforcement. The expanded-diameter high-pressure jet grouting anti-buoyancy pile includes a grouting consolidation body inside the pile hole and a jet grouting consolidation body outside the pile hole. The jet grouting consolidation body is a consolidation body formed by high-pressure jet grouting to the pile hole wall. The grouting consolidation body and the jet grouting consolidation body are a single unit. The movable reinforcement can be flipped and extended to embed into the jet grouting consolidation body corresponding to the soft strata, increasing the pile diameter and bearing capacity of the anti-buoyancy pile. This invention is used for the construction of anti-buoyancy piles.

Description

Technical Field

[0001] This invention relates to the field of basic science, specifically to an outward-extending anti-buoyancy anchor construction device, and an enlarged-diameter high-pressure jet grouting anti-buoyancy pile and its construction method. Background Technology

[0002] Anti-buoyancy anchors are primarily used to address the problem of buildings floating under high water levels. The anchor section is inserted deep into stable underground strata, utilizing the friction of the anchor section and its interaction with the surrounding soil to resist the buoyancy caused by groundwater, thus maintaining the building's stability. The friction between the anchor section and the soil is closely related to the roughness, length, and diameter of the anchor section, as well as the physical properties of the soil.

[0003] Patent CN 208685601 U discloses a composite expanded diameter anti-buoyancy steel anchor bolt, comprising a cement-soil layer and a columnar anchor bolt. Several outwardly extending connecting ribs are fixed to the outer wall of the anchor bolt, arranged along the anchor bolt's axis. The cement-soil layer includes a column and a variable diameter body, the diameter of which is larger than the diameter of the column. The variable diameter body is integrally connected to the column along its axis. On one hand, this patent utilizes the variable diameter construction of the cement-soil layer, where the weight of the soil presses down on the variable diameter body, fully leveraging the strength of both the anchor bolt and the soil layer, thus improving the pull-out resistance of the composite expanded diameter anti-buoyancy steel anchor bolt. On the other hand, the patent incorporates several connecting ribs on the anchor bolt, extending from the anchor bolt's surface and embedding them into the cement-soil layer, increasing the connection strength between the anchor bolt and the cement-soil layer, improving their overall integrity, and thereby enhancing the anti-buoyancy effect.

[0004] In the aforementioned patent, the connecting bar is fixedly installed on the outer wall of the anchor rod. The end of the connecting bar furthest from the anchor rod cannot extend beyond the pile hole; that is, the connecting bar cannot be embedded in the reducer body, otherwise the anchor rod cannot be inserted into the pile hole. Because the connecting bar is relatively short, it cannot effectively increase the connection strength between the anchor rod and the cement-soil layer. The connecting bar also affects the lowering of the anchor rod, causing problems such as anchor rod bending and failure to be lowered to the predetermined position. Furthermore, both the column and the reducer body are constructed using a high-pressure jet grouting machine. The strength of the column and the reducer body themselves is not high, making it difficult to effectively improve the pull-out resistance that the anchor rod can withstand.

[0005] Soft sand layers under high water table conditions often pose a challenge in engineering construction due to their loose structure and weak bearing capacity. The instability of these soil layers directly affects the bearing capacity of the foundation and the safety of the structure. Especially in environments with high groundwater levels, the soil layer not only lacks sufficient bearing capacity but may also be subject to the buoyancy of groundwater, causing buildings or structures to float and leading to safety issues. Currently, two common technologies for treating soft sand layers under high water table conditions are high-pressure jet grouting and anti-buoyancy anchors. High-pressure jet grouting mixes high-pressure jet grout with the soil layer to form reinforced piles, thereby improving the bearing capacity and stability of the foundation. Anti-buoyancy anchors, on the other hand, install anchors in the soil layer and use bonding materials to firmly bond the anchors to the soil, thus resisting the buoyancy of groundwater. Currently, construction sites typically employ high-pressure jet grouting and anti-buoyancy anchor technology separately. High-pressure jet grouting is performed first, and after the soil layer is reinforced, the anti-buoyancy anchors are installed. These two steps need to be carried out alternately, which often requires a long waiting time and significant investment of equipment and manpower. Summary of the Invention

[0006] The present invention first provides an outward-extending anti-buoyancy anchor construction device, the purpose of which is to increase the pull-out resistance that the anti-buoyancy anchor can withstand and improve the pile quality of anti-buoyancy piles.

[0007] The technical solution adopted in this invention is: an outward-extending anti-buoyancy anchor construction device, including a pile head, a casing, and anti-buoyancy reinforcement bars. The top of the pile head is provided with a threaded joint, and the lower end of the casing is provided with a threaded joint that matches the threaded joint at the top of the pile head and is threadedly connected to the pile head. There is at least one anti-buoyancy reinforcement bar, and each anti-buoyancy reinforcement bar is arranged along the center line of the casing and located inside the casing. The lower end of each anti-buoyancy reinforcement bar is fixedly connected to the pile head. At least one flip-embedded component is fixed on the outer periphery of the anti-buoyancy reinforcement bar. The flip-embedded component includes a fixed reinforcement bar and a movable reinforcement bar. The fixed reinforcement bar is arranged radially along the casing. One end of the fixed reinforcement bar is fixedly connected to the anti-buoyancy reinforcement bar, and the other end of the fixed reinforcement bar is rotatably connected to the movable reinforcement bar. The movable reinforcement bar can be rotated so that it is completely within the range corresponding to the casing, or it can be rotated so that part of the movable reinforcement bar is outside the range corresponding to the casing. The fixed reinforcement bar and the anti-buoyancy reinforcement bars and movable reinforcement bars at both ends are located in the same vertical plane, and the rotation range of the movable reinforcement bar around the fixed reinforcement bar is above the horizontal plane corresponding to the fixed reinforcement bar.

[0008] To facilitate the installation of the outward-extending anti-buoyancy anchor bolt construction device, the pile head is further divided into upper and lower sections vertically. The lower section of the pile head is conical or pyramidal, and the upper section is cylindrical or frustum-shaped with a larger bottom and a smaller top. The diameter of the top surface of the pile head is consistent with the outer diameter of the casing, and the center line of the pile head coincides with the center line of the casing.

[0009] During construction, the casing needs to be rotated to detach from the pile head. To prevent the conical pile head from rotating with the casing during rotation, which would affect the detachment of the casing from the pile head, the lower section of the pile head is conical, and at least one positioning plate is fixed on the side of the cone. The plane corresponding to the positioning plate is vertical and passes through the center line of the pile head.

[0010] To ensure the strength of the pile head, furthermore: the pile head is made of metal, or the pile head includes a metal shell and reinforced concrete inside the metal shell.

[0011] To facilitate the connection between the anti-buoyancy reinforcement and the pile head, and to ensure the strength of the connection, a further step is taken: a connecting bar is provided at the center of the top surface of the pile head. The number of connecting bars is equal to the number of anti-buoyancy reinforcement bars. The lower section of each connecting bar is fixed inside the pile head, while the upper section of each connecting bar protrudes from the top surface of the pile head. The lower end of each anti-buoyancy reinforcement bar is fixedly connected to the lower end of each connecting bar. For example, the connecting bar and the anti-buoyancy reinforcement are fixedly connected by a connecting sleeve. The upper end of the connecting bar and the lower end of the anti-buoyancy reinforcement bar connected to it are located in the openings at both ends of the same connecting sleeve and are connected by thread or welding.

[0012] After the movable reinforcing bar of the flip-embedded component flips outward and downward, it can be inserted into the weak strata outside the pile hole range, and then embedded into the jet grouting consolidation body outside the pile hole range. Specifically: the end of the fixed reinforcing bar away from the anti-buoyancy reinforcing bar is provided with a first connecting seat, which has a shaft hole arranged horizontally. The end of the movable reinforcing bar is provided with a second connecting seat, which has a rotating shaft that passes through the shaft hole. The first or second connecting seat is also provided with a limiting baffle to limit the maximum and minimum angles formed between the fixed and movable reinforcing bars. The shaft hole of the first connecting seat is preferably eccentrically arranged, and the second connecting seat is eccentrically connected to the first connecting seat. When the lower end of the casing corresponds to the position of the flip-embedded component, pressing down or hammering the upper end of the casing will cause the movable reinforcing bar of the flip-embedded component to naturally flip and unfold and remain in the unfolded state.

[0013] To facilitate the outward and downward unfolding of the movable reinforcing bar of the rotating embedded component under the action of external force and insertion into the stratum outside the pile hole range, further: the maximum angle between the fixed reinforcing bar and the movable reinforcing bar is a straight angle, and the minimum angle between the fixed reinforcing bar and the movable reinforcing bar is a right angle or an obtuse angle.

[0014] A fixed embedding component, always located within the pile hole range, can be installed on the outer side of the anti-buoyancy reinforcement. This fixed embedding component is ultimately embedded in the grouting solidified body and will not enter the jet grouting solidified body. Furthermore, at least one fixed embedding component is inherently located on the outer side of the anti-buoyancy reinforcement, within the casing. To facilitate installation and ensure the stability of the fixed embedding component, specifically: the fixed embedding component includes a fixed casing and at least one steel bar segment fixed to the outer wall of the fixed casing. The anti-buoyancy reinforcement passes through the fixed casing and is welded in place. The steel bar segment is perpendicular to the anti-buoyancy reinforcement, or the end of the steel bar segment away from the anti-buoyancy reinforcement is inclined upwards and forms an acute angle with the anti-buoyancy reinforcement.

[0015] To ensure that the anti-buoyancy reinforcement is always arranged along the centerline of the casing during construction, at least one positioning ring is further fitted on the outside of the anti-buoyancy reinforcement. The positioning ring has an outer ring, a middle ring, and an inner ring on the horizontal plane. The outer ring, the middle ring, and the inner ring are all circular and their centers coincide. The casing is cylindrical. The outer ring is fitted with the inner wall of the casing with a clearance fit. The outer ring and the middle ring are connected by at least one connecting rod. The middle ring and the inner ring are connected by at least one connecting rod. The anti-buoyancy reinforcement is fixed between the middle ring and the inner ring.

[0016] This invention also provides an expanded-diameter high-pressure jet grouting anti-buoyancy pile, the purpose of which is to improve the pile formation quality of anti-buoyancy piles and enhance the pull-out resistance that the anti-buoyancy reinforcement can withstand. The expanded-diameter high-pressure jet grouting anti-buoyancy pile has a vertically arranged pile hole that penetrates the upper hard stratum and enters the lower soft stratum. The pile hole contains a grouting consolidation body, and the outside of the pile hole contains a jet grouting consolidation body. The grouting consolidation body is formed by placing any of the aforementioned outward-extending anti-buoyancy anchor bolt construction devices into the pile hole, removing the casing, filling aggregate, and grouting fluid. The jet grouting consolidation body is formed by high-pressure jet grouting into the pile hole wall. The grouting consolidation body and the jet grouting consolidation body are a single unit, and the movable reinforcement of the inverted embedded component unfolds and embeds into the jet grouting consolidation body corresponding to the soft stratum.

[0017] The beneficial effects of this invention's outward-extending anti-buoyancy anchor construction device and expanded-diameter high-pressure jet grouting anti-buoyancy pile are as follows: The pile head and casing are connected. By pressing down or hammering the upper end of the casing, the entire anti-buoyancy anchor construction device can be inserted to a predetermined depth, ensuring that the pile head is inserted into the predetermined position within the pile hole. The anti-buoyancy reinforcement and the flip-embedding assembly are both located inside the casing, and the lower end of the anti-buoyancy reinforcement is fixedly connected to the pile head. The flip-embedding assembly does not affect the insertion of the anti-buoyancy anchor at all. After the outward-extending anti-buoyancy anchor construction device is inserted into the borehole, the casing is rotated to detach it from the pile head. The casing is then removed, and the movable reinforcement of the flip-embedding assembly flips and unfolds, inserting into the stratum outside the pile hole range. It then embeds itself into the jet grouting consolidation body outside the pile hole range, fixing the reinforcement embedded in the grouting consolidation body. The grouting consolidation body and the jet grouting consolidation body solidify into a whole, significantly improving the pile diameter and bearing capacity of the anti-buoyancy pile, and increasing the pull-out resistance that the anti-buoyancy reinforcement can withstand. This invention improves the pile formation quality of anti-buoyancy piles and enhances the pull-out resistance of anti-buoyancy steel bars.

[0018] The present invention also provides a construction method for an expanded-diameter high-pressure jet grouting anti-buoyancy pile. This construction method is both the method of using the first topic "outward-extending anti-buoyancy anchor construction device" and the construction method of the second topic "expanded-diameter high-pressure jet grouting anti-buoyancy pile". The purpose is the same: to increase the pull-out resistance that the anti-buoyancy anchor can withstand and improve the pile formation quality of the anti-buoyancy pile.

[0019] The construction method of the expanded diameter high-pressure jet grouting anti-buoyancy pile involves constructing anti-buoyancy piles in high-water-level strata where the upper layer is a hard stratum and the lower layer is a soft stratum. The method includes the following steps:

[0020] S1. Determine the location of the pile hole and construct it. The pile hole should penetrate hard strata and enter soft strata. Hard strata are generally gravel layers, while soft strata are generally sand layers or other strata that can be treated by high-pressure jet grouting. To improve the buoyancy resistance of the anti-buoyancy reinforcement, the pile hole should ideally penetrate the soft strata and reach or enter the good strata below the soft strata. Good strata are gravel layers or bedrock layers.

[0021] S2. High-pressure jet grouting is carried out from bottom to top inside the pile hole.

[0022] S3. Before the high-pressure jet grout solidifies, install a grouting pipe inside the casing of any of the above-mentioned "outward-facing anti-buoyancy anchor bolt construction devices", and insert the "outward-facing anti-buoyancy anchor bolt construction devices" into the pile hole by pressing down or hammering the upper end of the casing. The anti-buoyancy steel bars in the soft stratum are equipped with a flipping embedding component.

[0023] To further improve the quality of anti-buoyancy piles, the following further measures are taken: the anti-buoyancy reinforcement is arranged with rotating embedded components at intervals in the segments within the pile hole; or, the segments of the anti-buoyancy reinforcement located in soft strata are provided with at least one rotating embedded component, and the segments of the anti-buoyancy reinforcement located in other strata are fixed with at least one fixed embedded component, which is located inside the casing.

[0024] To ensure that the anti-buoyancy reinforcement is always arranged along the centerline of the casing during construction, and to facilitate the installation of the grouting pipe, the following further measures are taken: at least one positioning ring is fitted on the outside of the anti-buoyancy reinforcement. The positioning ring has an outer ring, a middle ring, and an inner ring on the horizontal plane. The outer ring, the middle ring, and the inner ring are all circular and their centers coincide. The casing is cylindrical. The outer ring is fitted with the inner wall of the casing with a clearance fit. The outer ring and the middle ring are connected by at least one connecting rod, and the middle ring and the inner ring are connected by at least one connecting rod. The anti-buoyancy reinforcement is fixed between the middle ring and the inner ring. The grouting pipe is clamped in the inner ring of each positioning ring, and the grout outlet of the grouting pipe is located at the lower end of the casing.

[0025] S4. Rotate the casing to detach it from the pile head.

[0026] S5. Fill the casing with aggregate and lift the casing. Use a layered method of filling the aggregate and gradually lifting the casing until the casing is pulled out of the pile hole and the pile hole is filled with aggregate. Control the active steel bar of the rotating embedded component to rotate and unfold and insert into the soft stratum outside the pile hole.

[0027] The following are several methods for controlling the movable reinforcing bars of the flip-embedded assembly to flip and unfold and insert into the soft strata outside the pile hole. Specifically: In step S5, when the lower end of the casing corresponds to the position of the flip-embedded assembly, the movable reinforcing bars of the flip-embedded assembly are flipped and unfolded and inserted into the soft strata outside the pile hole by pressing down or hammering the upper end of the casing; or, when the lower end of the casing exceeds the highest flip-embedded assembly, the movable reinforcing bars of each flip-embedded assembly are flipped and unfolded and inserted into the soft strata outside the pile hole by lifting the anti-buoyancy reinforcing bars; or, an elastic element is provided between the fixed reinforcing bars and the movable reinforcing bars of the flip-embedded assembly to allow the movable reinforcing bars to unfold automatically, and the movable reinforcing bars unfold automatically during the lifting of the casing.

[0028] To improve the density of the aggregate and promote its diffusion into the weak strata outside the pile hole, the aggregate in step S5 is pebbles with a diameter of 0.5 to 2.0 cm. After the pebbles are filled in layers, they are also vibrated.

[0029] S6. Grout is injected into the pile hole through the grouting pipe and cured. A grouting solidified body is formed inside the pile hole, and a jet grouting solidified body is formed outside the pile hole. The grouting solidified body and the jet grouting solidified body solidify into a whole.

[0030] The beneficial effects of the construction method for the expanded-diameter high-pressure jet grouting anti-buoyancy pile of this invention are as follows: Anti-buoyancy anchor bolt construction is carried out immediately after high-pressure jet grouting. By combining high-pressure jet grouting technology with anti-buoyancy anchor bolt technology, the waste of equipment and manpower caused by repeated pre-drilling of anti-buoyancy anchor bolts in the later stages is avoided, and the construction period is also saved. When the outward-extending anti-buoyancy anchor bolt construction device is inserted into the pile hole, the flip-embedded component is located inside the casing. The movable steel bar of the flip-embedded component cannot be unfolded or cannot be fully unfolded, and the flip-embedded component does not affect the insertion of the anti-buoyancy anchor bolt at all. The pile head is connected to the casing. By pressing down or hammering the upper end of the casing, the entire anti-buoyancy anchor bolt construction device can be inserted to the predetermined depth, ensuring that the pile head is inserted into the predetermined position in the pile hole. After the casing is separated from the pile head, aggregate is filled into the casing. The aggregate not only fills the pile hole but also diffuses into the weak strata, making the strength of the jet grouting consolidation body corresponding to the weak strata higher. When the movable reinforcing steel of the flip-embedded component is flipped and unfolded by pressing down or hammering the upper end of the casing, the lower end of the casing also compresses the filled aggregate, increasing the density of the aggregate in the pile hole and promoting the diffusion of the aggregate into the weak stratum. After the casing is removed from the pile hole, the movable reinforcing steel of the flip-embedded component automatically or under external force flips and unfolds outward and downward, inserting into the weak stratum outside the pile hole range, and finally embedding into the jet grouting consolidation body corresponding to the weak stratum, realizing the outward expansion of the anti-buoyancy pile in the weak interlayer. The grouting consolidation body and the jet grouting consolidation body solidify into a whole, effectively increasing the pile diameter and strength of the anti-buoyancy pile located in the weak stratum. This invention improves the pile formation quality of the anti-buoyancy pile and enhances the pull-out resistance that the anti-buoyancy reinforcing steel can withstand. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a structure of an embodiment of the outward-extending anti-buoyancy anchor bolt construction device of the present invention.

[0032] Figure 2 yes Figure 1 A schematic diagram of the flip-embedded component before it is unfolded in the embodiment shown.

[0033] Figure 3 yes Figure 1 A schematic diagram of the unfolded flip-embedded component in the illustrated embodiment.

[0034] Figure 4 yes Figure 1 A schematic diagram of an example of a fixed embedded component in the illustrated embodiment.

[0035] Figure 5 yes Figure 1 A structural schematic diagram on the horizontal section corresponding to the positioning ring.

[0036] Figure 6 This is a schematic diagram of a structural embodiment of the expanded diameter high-pressure jet grouting anti-buoyancy pile of the present invention.

[0037] Reference numerals in the attached drawings: 1. Pile head; 1-1. Metal outer shell; 1-2. Reinforced concrete; 1-3. Positioning plate; 1-4. Connecting bar; 2. Casing; 3. Anti-buoyancy reinforcement; 4. Tilting and embedding assembly; 4-1. Fixed reinforcement; 4-2. Movable reinforcement; 4-3. First connecting seat; 4-4. Second connecting seat; 4-5. Limiting baffle; 5. Connecting sleeve; 6. Fixed embedding assembly; 6-1. Fixed cylinder; 6-2. Reinforcing bar segment; 7. Positioning ring; 7-1. Outer ring; 7-2. Middle ring; 7-3. Inner ring; 7-4. Connecting rod; 8-1. Hard stratum; 8-2. Soft stratum; 9. Pile hole; 9-1. Grouting consolidation body; 9-2. Jet grouting consolidation body. Detailed Implementation

[0038] The invention will now be further described with reference to the accompanying drawings.

[0039] The first subject of this invention is an outward-extending anti-buoyancy anchor construction device for constructing anti-buoyancy anchors within pile holes. For example... Figure 1 As shown, the outward-extending anti-buoyancy anchor construction device includes a pile head 1, a casing 2, and anti-buoyancy steel bars 3.

[0040] The top of the pile head 1 is equipped with a threaded connector, which can be either an external or internal thread. The lower end of the casing 2 is equipped with a threaded connector that matches the threaded connector on the top of the pile head 1 and is threadedly connected to the pile head 1. The casing 2 is generally a steel cylinder, and its horizontal cross-sectional shape can be any polygon. Since the pile hole 9 is generally circular, and the lower end of the casing 2 is equipped with a threaded connector, the casing 2 is generally a steel cylinder. The top surface of the pile head 1 is generally circular to accommodate the threaded connector, and the diameter of the top surface of the pile head 1 is the same as the outer diameter of the casing 2.

[0041] To facilitate the placement of threaded joints on pile head 1, pile head 1 is vertically divided into upper and lower sections. The lower section of pile head 1 is conical or pyramidal, and the upper section is cylindrical or a frustum-shaped structure, with the bottom surface of the frustum overlapping the bottom surface of the cone. Figure 1As shown. The upper section of the pile head 1 is shaped like a frustum, wider at the bottom and narrower at the top. This reduces the friction between the casing 2 and the wall of the pile hole 9 during the insertion of the anti-buoyancy anchor device, thereby reducing the resistance during insertion. The centerline of the pile head 1 coincides with the centerline of the casing 2. The casing 2 needs to be rotated to detach from the pile head 1 during construction. To prevent the pile head 1 and casing 2 from rotating together when the casing 2 is rotated, thus affecting the detachment of the casing 2 from the pile head 1, the lower section of the pile head 1 is conical. At least one positioning plate 1-3 is fixed to the side of the cone. The plane corresponding to the positioning plate 1-3 is vertical and passes through the centerline of the pile head 1. The positioning plate 1-3 is inserted into the soil below the pile head 1, making it difficult for the pile head 1 to rotate around its centerline. There are two or more positioning plates 1-3, which are evenly distributed. The positioning plates 1-3 also serve as guides during the insertion of the pile head 1. The pile head 1 has no specific material requirements, as long as its hardness and strength are sufficient; it can be made of metal or reinforced concrete. To ensure the strength of the pile head 1, it is preferably made of metal, generally steel; or... Figure 1 As shown, the pile head 1 includes a metal shell 1-1 and reinforced concrete 1-2 inside the metal shell 1-1. The reinforcement of the reinforced concrete 1-2 can be arranged radially along the pile head 1 and fixedly connected to the metal shell 1-1. The metal shell 1-1 serves as a casting template and also improves the flatness of the pile head 1 surface. The top of the metal shell 1-1 is also convenient for setting threaded joints.

[0042] At least one anti-buoyancy reinforcement bar 3 is provided, and each anti-buoyancy reinforcement bar 3 is arranged along the centerline of the casing 2 and located inside the casing 2. The lower end of each anti-buoyancy reinforcement bar 3 is fixedly connected to the pile head 1. The anti-buoyancy reinforcement bar 3 is firmly connected to the pile head 1. The anti-buoyancy reinforcement bar 3 can be directly embedded in the concrete inside the pile head 1, or the pile head 1 can be provided with a joint for connecting to the anti-buoyancy reinforcement bar 3. For example, see Figure 1 A connecting bar 1-4 is provided at the center of the top surface of the pile head 1. The number of connecting bars 1-4 is equal to the number of anti-buoyancy steel bars 3. The lower section of each connecting bar 1-4 is fixed inside the pile head 1, for example, the lower section of the connecting bar 1-4 is fixedly connected to the reinforcement of the reinforced concrete 1-2 inside the pile head 1. The upper section of each connecting bar 1-4 protrudes from the top surface of the pile head 1. The lower end of each anti-buoyancy steel bar 3 is fixedly connected to the upper end of each connecting bar 1-4. The connecting bars 1-4 and the anti-buoyancy steel bars 3 can be welded together or mechanically connected by other means. For example, the connecting bars 1-4 and the anti-buoyancy steel bars 3 are fixedly connected by a connecting sleeve 5. The upper end of the connecting bar 1-4 and the lower end of the anti-buoyancy steel bar 3 connected to it are located in the openings at both ends of the same connecting sleeve 5 and are threaded or welded together. Figure 1 As shown.

[0043] The anti-buoyancy reinforcement 3 is generally composed of multiple bars, forming an anti-buoyancy reinforcement bundle. Ideally, each anti-buoyancy reinforcement 3 should be arranged along the centerline of the casing 2. To ensure that the anti-buoyancy reinforcement 3 remains aligned with the centerline of the casing 2 throughout construction, at least one positioning ring 7 is fitted around the outside of each anti-buoyancy reinforcement 3. The positioning ring 7 serves to fix the anti-buoyancy reinforcement 3 near the centerline of the casing 2. There are generally multiple positioning rings 7, arranged at vertical intervals. See, for example... Figure 5 The positioning ring 7 has an outer ring 7-1, a middle ring 7-2, and an inner ring 7-3 on the horizontal plane. All three rings are circular with their centers coinciding. The outer ring 7-1 and the middle ring 7-2 are connected by at least one connecting rod 7-4, and the middle ring 7-2 and the inner ring 7-3 are also connected by at least one connecting rod 7-4. The connecting rods 7-4 make the outer ring 7-1, middle ring 7-2, and inner ring 7-3 a single unit. The outer ring 7-1 has a clearance fit with the inner wall of the casing 2, and its shape matches the shape of the casing 2, both being circular. The anti-buoyancy reinforcement 3 is fixed between the middle ring 7-2 and the inner ring 7-3. The spacing between the middle ring 7-2 and the inner ring 7-3 is preferably consistent with the diameter of the anti-buoyancy reinforcement 3, thereby fixing the position of the anti-buoyancy reinforcement 3. The inner hole of the inner ring 7-3 can be used to arrange the grouting pipe.

[0044] At least one flip-embedded component 4 is fixed to the outer periphery of the anti-buoyancy reinforcement 3. The flip-embedded component 4 has two states: a flipped and unfolded state and a non-flipped and unfolded state. When the flip-embedded component 4 is located inside the casing 2, it is in the non-flipped and unfolded state, such as... Figure 2 As shown. After the casing 2 of the outward-extending anti-buoyancy anchor bolt construction device is removed from the pile hole 9, the flip-embedded component 4 can be in a flipped-out state, as shown. Figure 3 As shown.

[0045] The flip-embedded component 4 includes a fixed reinforcing bar 4-1 and a movable reinforcing bar 4-2. The fixed reinforcing bar 4-1 is arranged radially along the casing 2. One end of the fixed reinforcing bar 4-1 is fixedly connected to the anti-buoyancy reinforcing bar 3, for example, by welding. The other end of the fixed reinforcing bar 4-1 is rotatably connected to the movable reinforcing bar 4-2. Regardless of how the movable reinforcing bar 4-2 rotates around the fixed reinforcing bar 4-1, the fixed reinforcing bar 4-1 and the anti-buoyancy reinforcing bars 3 at both ends and the movable reinforcing bar 4-2 are always located in the same vertical plane, and the movable reinforcing bar 4-2 is always located above the horizontal plane corresponding to the fixed reinforcing bar 4-1. The movable reinforcing bar 4-2 can rotate around the fixed reinforcing bar 4-1 in such a way that it is completely within the area corresponding to the casing 2, at which point both the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 are completely within the area corresponding to the casing 2; or it can rotate in such a way that it is partially outside the area corresponding to the casing 2, at which point the fixed reinforcing bar 4-1 is completely within the area corresponding to the casing 2, and the movable reinforcing bar 4-2 is partially outside the area corresponding to the casing 2. The total length of the interconnected fixed reinforcing bar 4-1 and movable reinforcing bar 4-2 is greater than the radius of the casing 2, allowing the movable reinforcing bar 4-2 to expand outwards after unfolding. The length of the fixed reinforcing bar 4-1 is preferably the same as the radius of the casing 2. One end of the fixed reinforcing bar 4-1 connecting to the movable reinforcing bar 4-2 abuts against the inner wall of the casing 2, and the movable reinforcing bar 4-2 can rotate to form a flat angle with the fixed reinforcing bar 4-1, allowing the movable reinforcing bar 4-2 to expand outwards as much as possible. After the movable reinforcing bar 4-2 of the flip-embedded component 4 is flipped outwards and downwards, it can be inserted into the soft strata outside the pile hole 9, and finally embedded in the jet grouting consolidation body 9-2.

[0046] The following is an embodiment in which the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 are rotatably connected. See also Figure 2 and Figure 3The fixed reinforcing bar 4-1, at the end furthest from the anti-buoyancy reinforcing bar 3, is provided with a first connecting seat 4-3. The first connecting seat 4-3 has a horizontally arranged shaft hole. The movable reinforcing bar 4-2, at one end, is provided with a second connecting seat 4-4. The second connecting seat 4-4 has a rotating shaft that passes through the shaft hole. The first connecting seat 4-3 or the second connecting seat 4-4 is also provided with a limiting baffle 4-5 to limit the extreme angle formed between the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2. The shaft hole of the first connecting seat 4-3 is preferably eccentrically arranged, and the second connecting seat 4-4 is eccentrically connected to the first connecting seat 4-3. When the lower end of the casing 2 corresponds to the position of the flip-embedded component 4, pressing down or hammering the upper end of the casing 2 causes the movable reinforcing bar 4-2 of the flip-embedded component 4 to naturally flip and unfold and remain in the unfolded state. The extreme angle formed between the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 includes the maximum angle and the minimum angle. The movable reinforcing bar 4-2 unfolds after the casing 2 is removed. To facilitate the unfolding of the movable reinforcing bar 4-2 under external force, such as by utilizing the downward pressure of the casing 2, the minimum angle formed between the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 is a right angle or an obtuse angle, and the movable reinforcing bar 4-2 abuts against the casing 2 when inside the casing 2. To improve the buoyancy resistance of the anti-buoyancy reinforcing bar 3, the maximum angle formed between the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 is a straight angle, meaning that both the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2 are arranged radially along the anti-buoyancy reinforcing bar 3. To enable the movable reinforcing bar 4-2 to unfold automatically, or to have a tendency to unfold automatically, an elastic element that allows the movable reinforcing bar 4-2 to unfold automatically can be provided between the fixed reinforcing bar 4-1 and the movable reinforcing bar 4-2. The elastic element can be a tension spring, spring, torsion spring, elastic sheet, etc. The movable reinforcing bar 4-2 unfolds automatically during the lifting of the casing 2.

[0047] To improve the buoyancy resistance of the anti-buoyancy reinforcement 3, a fixed embedding component 6 can be fixedly installed on the outside of the anti-buoyancy reinforcement 3, always located within the pile hole 9. The fixed embedding component 6 is always located inside the casing 2 and is eventually embedded in the grouting solidified body 9-1. The fixed embedding component 6 will not enter the jet grouting solidified body 9-2. At least one fixed embedding component 6 is also fixed on the outside of the anti-buoyancy reinforcement 3, and the fixed embedding component 6 is located inside the casing 2, such as... Figure 4 As shown, the fixed embedded component 6 includes a fixed cylinder 6-1 and at least one steel bar segment 6-2 fixed to the outer wall of the fixed cylinder 6-1. The anti-buoyancy steel bar 3 passes through the fixed cylinder 6-1 and is welded and fixed. The steel bar segment 6-2 is welded and connected to the fixed cylinder 6-1. Different steel bar segments 6-2 are kept apart to avoid crossing. They are placed at equal intervals according to the circumferential angle. The steel bar segment 6-2 is perpendicular to the anti-buoyancy steel bar 3, or the end of the steel bar segment 6-2 away from the anti-buoyancy steel bar 3 is inclined upward and forms an acute angle with the anti-buoyancy steel bar 3.

[0048] The second subject of this invention is an enlarged-diameter high-pressure jet grouting anti-buoyancy pile, which is actually an anti-buoyancy pile obtained by constructing the first subject mentioned above. See also Figure 6 The expanded-diameter high-pressure jet grouting anti-buoyancy pile has vertically arranged pile holes 9 that penetrate the upper hard stratum 8-1 and enter the lower soft stratum 8-2. The pile holes 9 can also penetrate the soft stratum 8-2 to reach or enter the good stratum below it. The hard stratum 8-1 is generally a pebble layer, the soft stratum 8-2 is generally a sand layer or other strata that can be treated by high-pressure jet grouting, and the good stratum is generally a pebble layer or bedrock layer. The pile hole 9 contains a grouting consolidation body 9-1, and the pile hole 9 is surrounded by a jet grouting consolidation body 9-2. The grouting consolidation body 9-1 is formed by placing the aforementioned outward-extending anti-buoyancy anchor bolt construction device into the pile hole 9, removing the casing 2, filling with aggregate, and grouting grout. To facilitate aggregate diffusion and dense filling, the aggregate is preferably pebbles, for example, pebbles with a diameter of 0.5–2.0 cm. Filling is done in layers and gradually. The jet grouting solidified body 9-2 is a solidified body formed by high-pressure jet grouting into the wall of pile hole 9. The grouting solidified body 9-1 and the jet grouting solidified body 9-2 solidify simultaneously and become a whole. The movable steel bar 4-2 of the inverted embedded component 4 unfolds and embeds into the jet grouting solidified body 9-2 corresponding to the weak stratum 8-2.

[0049] The third subject of this invention is a construction method for an expanded-diameter high-pressure jet grouting anti-buoyancy pile. This construction method is both the method of using the first subject, "outward-extending anti-buoyancy anchor bolt construction device," and the construction method for the second subject, "expanded-diameter high-pressure jet grouting anti-buoyancy pile." See also Figure 6 The construction method of the expanded diameter high-pressure jet grouting anti-buoyancy pile involves constructing anti-buoyancy piles in a high-water-level stratum with a hard upper layer (8-1) and a soft lower layer (8-2), including the following steps.

[0050] S1. Determine the location of pile hole 9 and construct it. Pile hole 9 penetrates the hard stratum 8-1 from top to bottom and enters the soft stratum 8-2. When determining the location of pile hole 9, it is generally necessary to excavate to 50cm above the base elevation and survey and mark the planar position of pile hole 9. During the construction of pile hole 9, a down-the-hole drill is used for pilot drilling. After drilling, a 110mm diameter PVC pipe is inserted, with the pre-embedded length varying with the hole depth. Subsequently, the casing used for drilling is systematically pulled out. Ideally, pile hole 9 should also penetrate the soft stratum 8-2 to reach or enter the underlying good stratum 8-3, which is generally a pebble layer or bedrock layer.

[0051] S2. High-pressure jet grouting is carried out from bottom to top inside pile hole 9.

[0052] Insert the jetting pipe into pile hole 9. Once the nozzle of the jetting pipe reaches the design elevation, grouting can begin. For example, use ordinary Portland cement with a strength grade of P.0.42.5 and a water-cement ratio of 0.8–1.0. After the jetting grouting parameters reach the specified values, immediately raise the jetting pipe according to the requirements of the high-pressure jet grouting process, rotating it upwards to spray grout 500mm above the top surface of the soft stratum 8-2. The overlap length of the jetting pipe during segmented lifting should be no less than 100mm. If there is no pressure and backflow of grout in the pilot hole section, quickly pull out the jetting pipe. To prevent the grout from solidifying and shrinking, affecting the pile top elevation, measures such as grout backfilling or a second grouting at the original hole location are also required.

[0053] S3. Before the high-pressure jet grout solidifies, install a grouting pipe inside the casing 2 of the first topic above, "Extended Anti-buoyancy Anchor Construction Device", and insert the "Extended Anti-buoyancy Anchor Construction Device" into the pile hole 9 by pressing down or hammering the upper end of the casing 2.

[0054] The construction of the "outward-extending anti-buoyancy anchor bolt construction device" is described in the first topic above. The entire segment of the anti-buoyancy reinforcing bar 3 located within the pile hole 9 can be intermittently arranged with rotating embedding components 4. In this case, the rotating embedding components 4 located in the hard stratum 8-1 remain stationary, while those located in the soft stratum 8-2 rotate and unfold. Alternatively, the segment of the anti-buoyancy reinforcing bar 3 located in the soft stratum 8-2 is equipped with rotating embedding components 4, while the segments of the anti-buoyancy reinforcing bar 3 located in other strata are fixed with fixed embedding components 6, which can be one or more. These other strata are strata other than the soft stratum 8-2, including the hard stratum 8-1. When the anti-buoyancy reinforcing bar 3 is fitted with positioning rings 7, the grouting pipe can be temporarily fixed in the inner ring 7-3 of each positioning ring 7 to facilitate installation, with the grout outlet end of the grouting pipe located at the lower end of the casing 2.

[0055] The "outward-extending anti-buoyancy anchor bolt construction device" is generally inserted into the pile hole 9 by vibrating a hammer to drive the casing 2. The pile head 1 should ideally penetrate the weak stratum 8-2 to reach or enter the good stratum below. During the lowering process, the force and speed of the vibrating hammer should be strictly controlled to avoid grout return from the treated stratum, while ensuring that the verticality of the hole meets the design requirements.

[0056] S4. Rotate the casing 2 to separate it from the pile head 1. After the "outward-extending anti-buoyancy anchor construction device" is inserted into the predetermined position, use the clamp to rotate the upper end of the casing 2 to separate it from the pile head 1.

[0057] S5. Fill the casing 2 with aggregate and lift the casing 2, using a layered filling and gradual lifting method until the casing 2 is pulled out of the pile hole 9 and the pile hole 9 is filled with aggregate. When filling the aggregate in layers, the filling thickness must be controlled within a certain range to ensure that the aggregate is evenly and densely filled inside the casing 2, avoiding voids. To facilitate aggregate diffusion and dense filling, pebbles are preferred, for example, pebbles with a diameter of 0.5-2.0 cm. After filling the pebbles in layers, they are also vibrated. After the pebbles have filled to a certain thickness, they are vibrated to ensure dense filling and to allow the pebbles to diffuse around the pile hole 9. Then, the casing 2 is lifted to a certain height, so that the bottom elevation of the casing 2 is slightly lower than the top elevation of the pebbles. Pebbles are then filled and vibrated again, and this operation is repeated. After filling with pebbles, hammering the top of the casing 2 also makes the pebbles denser and diffuses them into the surrounding strata. When the casing 2 is raised to the height corresponding to the flip-embedded component 4 and it is necessary to unfold the flip-embedded component 4, the movable steel bar 4-2 of the flip-embedded component 4 is flipped and unfolded by pressing down or hammering the upper end of the casing 2 and inserted into the soft stratum 8-2 outside the pile hole 9; or, when the lower end of the casing 2 exceeds the highest flip-embedded component 4, the movable steel bar 4-2 of each flip-embedded component 4 is flipped and unfolded by lifting the anti-buoyancy steel bar 3 and inserted into the soft stratum 8-2 outside the pile hole 9. After the casing 2 is pulled out of the pile hole, the pebbles should be replenished in time to ensure the filling effect of the pebbles in the pile hole 9.

[0058] S6. Grout is injected into the pile hole 9 through the grouting pipe and cured. A grouting solidified body 9-1 is formed inside the pile hole 9, and a jet grouting solidified body 9-2 is formed outside the pile hole 9. The grouting solidified body 9-1 and the jet grouting solidified body 9-2 solidify into a whole.

[0059] For example, the grout is prepared using ordinary Portland cement of grade P.0.42.5, with a water-cement ratio of 0.45–0.50. The grout is a pure cement grout with a strength of M30, and the grouting pressure is 0.8–1.0 MPa. During grouting, if thick grout emerges from the borehole, grouting should be paused, and pressure should be reapplied after a short interval, for example, about 10 minutes. Grouting should be stopped when thick grout emerges again. Grouting should be completed within 24 hours after the pile hole is completed. If secondary grouting is required, the grouting pressure should be greater than 2.0 MPa. During the curing period, exposed anti-buoyancy reinforcing bars must not be touched by external force.

Claims

1. An outward-extending anti-buoyancy anchor construction device, comprising a pile head (1), a casing (2), and anti-buoyancy reinforcing bars (3), wherein the top of the pile head (1) is provided with a threaded joint, and the lower end of the casing (2) is provided with a threaded joint that is compatible with the threaded joint at the top of the pile head (1) and threadedly connected to the pile head (1), and there is at least one anti-buoyancy reinforcing bar (3), each anti-buoyancy reinforcing bar (3) is arranged along the center line of the casing (2) and located inside the casing (2), and the lower end of each anti-buoyancy reinforcing bar (3) is fixedly connected to the pile head (1), characterized in that: At least one flip-embedded component (4) is fixed to the outer periphery of the anti-buoyancy steel bar (3). The flip-embedded component (4) includes a fixed steel bar (4-1) and a movable steel bar (4-2). The fixed steel bar (4-1) is arranged radially along the casing (2). One end of the fixed steel bar (4-1) is fixedly connected to the anti-buoyancy steel bar (3). The other end of the fixed steel bar (4-1) is provided with a first connecting seat (4-3) and is rotatably connected to a second connecting seat (4-4) at one end of the movable steel bar (4-2). The first connecting seat (4-3) is provided with a shaft hole arranged horizontally and eccentrically. The second connecting seat (4-4) is provided with a rotating shaft that passes through the shaft hole. The second connecting seat (4-4) is eccentrically connected to the first connecting seat (4-3). The first connecting seat (4-3) or the second connecting seat (4-4) is also provided to limit the maximum clamping between the fixed steel bar (4-1) and the movable steel bar (4-2). The limiting baffle (4-5) of the angle and the minimum included angle, the movable steel bar (4-2) can be rotated to the point that the movable steel bar (4-2) is completely within the range corresponding to the casing (2), or it can be rotated to the point that the movable steel bar (4-2) is partially outside the range corresponding to the casing (2). The fixed steel bar (4-1) and the anti-buoyancy steel bars (3) at both ends and the movable steel bar (4-2) are located on the same vertical plane, and the rotation range of the movable steel bar (4-2) around the fixed steel bar (4-1) is above the horizontal plane corresponding to the fixed steel bar (4-1). The maximum included angle between the fixed steel bar (4-1) and the movable steel bar (4-2) is a straight angle, and the minimum included angle between the fixed steel bar (4-1) and the movable steel bar (4-2) is a right angle or an obtuse angle. An elastic element is provided between the fixed steel bar (4-1) and the movable steel bar (4-2) to allow the movable steel bar (4-2) to automatically unfold during the lifting of the casing (2). When the casing (2) is raised to the position corresponding to the position of the flip-embedded component (4), the movable steel bar (4-2) of the flip-embedded component (4) can be flipped and inserted into the soft stratum outside the pile hole by pressing down or hammering the upper end of the casing (2); or, when the lower end of the casing (2) exceeds the highest position of the flip-embedded component (4), the movable steel bar (4-2) of each flip-embedded component (4) can be flipped and inserted into the soft stratum outside the pile hole by raising the anti-buoyancy steel bar (3); The pile head (1) is vertically divided into upper and lower sections. The lower section of the pile head (1) is conical or pyramidal. At least one positioning plate (1-3) is fixed on the side of the cone. The plane corresponding to the positioning plate (1-3) is vertical and passes through the center line of the pile head (1). The upper section of the pile head (1) is cylindrical or frustum-shaped with a larger bottom and a smaller top. The diameter of the top surface of the pile head (1) is consistent with the outer diameter of the casing (2), and the center line of the pile head (1) coincides with the center line of the casing (2). At least one positioning ring (7) is also fitted on the outside of the anti-buoyancy steel bar (3). The positioning ring (7) has an outer ring (7-1), a middle ring (7-2) and an inner ring (7-3) on the horizontal plane. The outer ring (7-1), the middle ring (7-2) and the inner ring (7-3) are all circular and their centers coincide. The protective sleeve (2) is a cylinder. The outer ring (7-1) is fitted with the inner wall of the protective sleeve (2) with a clearance. The outer ring (7-1) and the middle ring (7-2) are connected by at least one connecting rod (7-4). The middle ring (7-2) and the inner ring (7-3) are connected by at least one connecting rod (7-4). The anti-buoyancy steel bar (3) is fixed between the middle ring (7-2) and the inner ring (7-3).

2. The outward-extending anti-buoyancy anchor bolt construction device as described in claim 1, characterized in that: The pile head (1) is made of metal, or the pile head (1) includes a metal shell (1-1) and reinforced concrete (1-2) inside the metal shell (1-1).

3. The outward-extending anti-buoyancy anchor bolt construction device as described in claim 1, characterized in that: A connecting bar (1-4) is provided at the center of the top surface of the pile head (1). The number of connecting bars (1-4) is equal to the number of anti-buoyancy bars (3). The lower section of each connecting bar (1-4) is fixed inside the pile head (1), and the upper section of each connecting bar (1-4) is exposed on the top surface of the pile head (1). The lower end of each anti-buoyancy bar (3) is fixedly connected to the lower end of each connecting bar (1-4).

4. The outward-extending anti-buoyancy anchor bolt construction device as described in claim 3, characterized in that: The connecting bar (1-4) and the anti-buoyancy bar (3) are fixedly connected by the connecting sleeve (5). The upper end of the connecting bar (1-4) and the lower end of the anti-buoyancy bar (3) connected to it are located in the openings at both ends of the same connecting sleeve (5) and are connected by thread or welding.

5. The outward-extending anti-buoyancy anchor bolt construction device as described in any one of claims 1 to 4, characterized in that: The outer side of the anti-buoyancy steel bar (3) also has at least one fixed embedding component (6), which is located inside the casing (2). The fixed embedding component (6) includes a fixed casing (6-1) and at least one steel bar segment (6-2) fixed to the outer wall of the fixed casing (6-1). The anti-buoyancy steel bar (3) passes through the fixed casing (6-1) and is welded and fixed. The steel bar segment (6-2) is perpendicular to the anti-buoyancy steel bar (3), or the end of the steel bar segment (6-2) away from the anti-buoyancy steel bar (3) is inclined upward and forms an acute angle with the anti-buoyancy steel bar (3).

6. An expanded-diameter high-pressure jet grouting anti-buoyancy pile, wherein the pile hole (9) is arranged vertically and penetrates the upper hard stratum (8-1) into the lower soft stratum (8-2), the pile hole (9) contains a grouting solidified body (9-1), and the pile hole (9) contains a jet grouting solidified body (9-2), characterized in that: The grouting consolidation body (9-1) is a consolidation body formed by inserting the outward-spreading anti-buoyancy anchor bolt construction device as described in any one of claims 1 to 5 into the pile hole (9) and removing the casing (2), filling aggregate and grouting liquid. The jet grouting consolidation body (9-2) is a consolidation body formed by high-pressure jet grouting into the wall of the pile hole (9). The grouting consolidation body (9-1) and the jet grouting consolidation body (9-2) are a whole, and the movable steel bar (4-2) of the flip-embedded component (4) unfolds and embeds into the jet grouting consolidation body (9-2) corresponding to the weak stratum (8-2).

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