Construction method for large-diameter rotary drilling piles embedded in rock in exposed seabed

Abstract

This invention relates to the technical field of rotary drilling piles, and discloses a method for embedding and installing large-diameter rotary drilling pile casings and inner casings in exposed rock in marine areas. The method includes: 1) Lowering the outer casing into seawater, with its bottom abutting against the top of the exposed rock, forming an outer casing space; 2) Using a rotary drill bit to cut downwards around the exposed rock, forming an annular groove and a rock column, with the annular groove surrounding the rock column; 3) Lowering the inner casing into the outer casing space, with its lower part embedded in the annular groove, forming a lower section, and a lower annular cavity between the outer wall of the lower section and the inner wall of the annular groove; the upper part of the inner casing is exposed in the outer casing space, forming an upper section, and an upper annular cavity between the outer wall of the upper section and the inner wall of the outer casing; 4) Pulling out the outer casing. This method solves the problem of embedding casings for large-diameter rotary drilling piles in exposed rock in marine areas.

Description

Technical Field

[0001] This invention patent relates to the technical field of rotary drilling piles, specifically to a construction method for embedding and burying large-diameter rotary drilling piles with outer and inner casings in exposed rock in marine areas. Background Technology

[0002] With the development of the national marine economy, more and more offshore wind power projects, cross-sea bridges, large wharves, and other marine structures are being constructed. Among these projects, pile foundation engineering is a crucial component, especially in bare rock sea areas where the lack of soil layers poses a significant challenge to pile foundation construction.

[0003] In existing technologies, when constructing rotary drilling pile casings on bare rock surfaces in the sea, pile hammers are used for casing construction. However, the casing is obstructed by the rock surface and cannot be sunk. The stiffened part at the bottom is prone to inward bending, leading to grout leakage at the bottom of the casing. Furthermore, during drilling, the mechanical drilling tools are prone to colliding with the bent part of the casing, resulting in situations such as being unable to advance or getting the drill bit stuck. Although impact drilling can lower the casing, it is difficult to control the verticality of the casing, affecting the quality of subsequent drilling operations. Summary of the Invention

[0004] The purpose of this invention is to provide a method for embedding and installing outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas, aiming to solve the problem of difficult installation of casings for large-diameter rotary drilling piles in exposed rock in marine areas in the prior art.

[0005] This invention is implemented as follows: a method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed marine rock, comprising the following steps:

[0006] 1) The outer casing is lowered into the seawater, with the bottom of the outer casing abutting against the top of the bare rock, and the outer casing encloses and forms the outer casing space;

[0007] 2) Using a rotary drill bit to cut the bare rock downwards, an annular groove is formed in the bare rock, and a rock column is formed in the bare rock, with the annular groove surrounding the outer periphery of the rock column;

[0008] 3) An inner protective cylinder is lowered into the outer cylinder space. The lower part of the inner protective cylinder is embedded in the annular groove to form a lower section. The outer side wall of the lower section and the inner side wall of the annular groove have a lower annular cavity. The upper part of the inner protective cylinder is exposed in the outer cylinder space to form an upper section. The outer side wall of the upper section and the inner side wall of the outer protective cylinder have an upper annular cavity.

[0009] 4) Pull out the outer casing.

[0010] Optionally, in step 1), after the bottom of the outer casing abuts against the top of the bare rock, the outer casing is temporarily fixed while maintaining a vertical position.

[0011] In step 1), before lowering the outer casing, a special drill bit is used to drill and clean the bare rock.

[0012] In step 1), before lowering the outer casing, a rotary drilling rig is used to clear the backfill on the bare rock.

[0013] In step 4), before pulling out the outer casing, crushed sand is filled into the lower annular cavity and the upper annular cavity.

[0014] Optionally, the inner wall of the outer casing is provided with a plurality of positioning blocks, which are arranged at intervals along the circumference of the outer casing; in step 3), during the process of lowering the inner casing into the outer casing space, the positioning blocks abut against the outer wall of the inner casing.

[0015] Optionally, in step 3), multiple positioning blocks are set according to the deviation between the center of the outer casing and the center of the pile hole, so that after the multiple positioning blocks abut against the outer wall of the inner casing, the center of the inner casing is aligned with the center of the pile hole.

[0016] Optionally, in step 3), four positioning blocks are provided on the inner sidewall of the outer casing, and the four positioning blocks are arranged at equal intervals along the circumference of the outer casing.

[0017] Optionally, in step 3), the bottom of the lower section abuts against the bottom of the annular groove.

[0018] Optionally, in step 3), the top of the upper section extends above the outer casing.

[0019] Optionally, the bare rock has crushed sand. In step 4), during the process of pulling up the outer casing, the crushed sand on the bare rock is automatically added into the upper and lower annular cavities under the impact of seawater, filling the upper and lower annular cavities with crushed sand, and the crushed sand in the upper and lower annular cavities is in a compacted state.

[0020] Optionally, the bottom of the lower section has a bottom surface, the inner side of the bottom surface has a horizontally arranged horizontal surface, the outer side of the bottom surface has an inclined surface, the lower end of the inclined surface is connected to the outer periphery of the horizontal surface, and the upper end of the inclined surface is inclined upward and penetrates the outer periphery of the lower section.

[0021] The inclined surface is provided with a plurality of horizontal strips, which are spaced around the circumference of the inclined surface. Along the axial direction of the inner protective cylinder, adjacent horizontal strips are arranged in a staggered manner. The inner end of the horizontal strip is connected to the inclined surface, and the outer end of the horizontal strip extends outward and has a transverse gap with the inner sidewall of the annular groove.

[0022] In step 3), after the lower section abuts against the bottom of the annular groove, the horizontal surface abuts against the bottom of the annular groove, and the inclined surface is arranged upwards away from the bottom of the annular groove. The inclined surface and the bottom of the annular groove enclose a triangular annular cavity, and multiple horizontal strips are formed in the triangular annular cavity. During the process of filling the lower annular cavity and the upper annular cavity with crushed sand, the crushed sand fills the triangular annular cavity and wraps around the horizontal strips.

[0023] Optionally, the horizontal plane is recessed upwards to form a ring-shaped recessed area with an open bottom, and the recessed area is arranged around the lower section in a circumferential manner; a notch is formed on the outer side of the horizontal plane, and the triangular ring cavity communicates with the recessed area through the notch;

[0024] During the process of filling the lower and upper annular cavities with crushed sand, the crushed sand enters the recessed area through the notch and fills the recessed area completely.

[0025] Compared with existing technologies, the present invention provides a method for embedding outer and inner casings of large-diameter rotary drilling piles in exposed seabed rock. By lowering the outer casing to the exposed rock surface, seawater and sediment are isolated, providing drilling conditions for the rotary drill. Under the combined guiding effect of the outer casing and its own extra-long casing, the rotary drill forms a straight and complete annular groove. Then, the inner casing is lowered, its lower part embedded in the annular groove. The inner wall of the annular groove and the rock column limit the inner casing, preventing it from tilting and ensuring precise vertical placement. After the outer casing is pulled out, the alluvial deposits in the riverbed continuously fill and compact the lower annular cavity with crushed sand from beneath the rock surface, ensuring the inner casing does not shift or leak grout. This method is highly efficient, convenient, cost-effective, safe, and practical, effectively solving the problem of embedding casings for large-diameter rotary drilling piles in exposed seabed rock. Attached Figure Description

[0026] Figure 1 This is a construction diagram of step 2) provided by the present invention;

[0027] Figure 2 This is a construction diagram of step 2) provided by the present invention;

[0028] Figure 3 This is a construction diagram of step 3) provided by the present invention;

[0029] Figure 4 This is a construction diagram of step 4) provided by the present invention;

[0030] Figure 5 This is a cross-sectional schematic diagram of the bottom of the lower section provided by the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0033] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0034] Reference Figure 1-5 The image shows a preferred embodiment of the present invention.

[0035] The present invention provides a method for embedding and burying a 100-diameter rotary drilling pile outer casing 100 and an inner casing 300 in exposed rock in the sea, comprising the following steps:

[0036] 1) The outer casing 100 is lowered into the seawater, with the bottom of the outer casing 100 abutting against the top of the bare rock 10, and the outer casing 100 encloses and forms the outer casing space;

[0037] 2) Using a rotary drill bit with the diameter 200 facing downwards, a circular groove 11 is formed in the bare rock 10, and a rock column 12 is formed in the bare rock 10. The circular groove 11 surrounds the outer periphery of the rock column 12.

[0038] 3) The inner casing 300 is lowered into the outer casing space. The lower part of the inner casing 300 is embedded in the annular groove 11 to form a lower section. The outer side wall of the lower section and the inner side wall of the annular groove 11 have a lower annular cavity. The upper part of the inner casing 300 is exposed in the outer casing space to form an upper section. The outer side wall of the upper section and the inner side wall of the outer casing 100 have an upper annular cavity.

[0039] 4) Pull out the outer casing 100.

[0040] The above-mentioned construction method for embedding the outer casing 100 and inner casing 300 of the large-diameter rotary drilling pile in exposed rock in the sea area involves lowering the outer casing 100 to the exposed rock surface on the seabed, isolating seawater and silt, and providing drilling conditions for the rotary drill 200. Under the combined guiding effect of the outer casing 100 and its own extra-long casing, the rotary drill 200 forms a straight and complete annular groove 11. Then, the inner casing 300 is lowered to be embedded in the annular groove 11. Under the double constraint of the rock column 12 and the inner wall of the annular groove 11, the inner casing 300 is prevented from deviating, ensuring that the inner casing 300 is accurately and vertically lowered into place. After the outer casing 100 is pulled out, the alluvial sand in the riverbed causes the crushed sand 500 under the rock surface to continuously fill and compact the lower annular cavity, ensuring that the inner casing 300 does not deviate or leak grout. In this way, it is efficient, convenient, cost-effective, safe and practical, and effectively solves the problem of burying 10-diameter rotary drilling pile casings on bare rock in the sea.

[0041] In step 1), after the bottom of the outer casing 100 abuts against the top of the bare rock 10, the outer casing 100 is temporarily fixed after being kept vertical; this provides better drilling conditions for the roller cone drill 200 and ensures that the roller cone drill 200 drills vertically.

[0042] In step 1), before lowering the outer casing 100, a special drill bit is used to drill and clean the bare rock; this helps to ensure the casing is lowered stably.

[0043] In step 1), before lowering the outer casing 100, the backfill on the bare rock is cleared using a rotary drilling rig. In this way, if there is backfill that cannot be placed directly on the rock surface, the rotary drilling rig is used to clear it directly, so as to ensure that the casing is placed stably on the rock surface and to provide a guarantee for subsequent circumferential cutting construction.

[0044] In step 4), before pulling out the outer casing 100, crushed sand 500 is filled into the lower and upper annular cavities. In this way, by pre-filling with crushed sand 500, after pulling out the outer casing 100, the crushed sand 500 will quickly fill the lower annular cavity and the outer periphery of the outer casing 100.

[0045] Multiple positioning blocks 400 are provided on the inner wall of the outer casing 100, and the positioning blocks 400 are arranged at intervals along the circumference of the outer casing 100. In step 3), during the process of lowering the inner casing 300 into the outer casing space, the positioning blocks 400 abut against the outer wall of the inner casing 300. In this way, the inner casing 300 is accurately aligned with the center of the pile. During the lowering process of the inner casing 300, it is simultaneously constrained by the positioning blocks 400 above and the embedded rock column 12 below, preventing the inner working casing from tilting and ensuring that the casing is accurately and vertically lowered into place.

[0046] Specifically, in step 3), based on the deviation between the center of the outer casing 100 and the center of the pile hole, multiple positioning blocks 400 are set accordingly, so that after the multiple positioning blocks 400 abut against the outer wall of the inner casing, the center of the inner casing 300 is aligned with the center of the pile hole. This ensures alignment.

[0047] In step 3), four positioning blocks 400 are provided on the inner side wall of the outer casing 100, and the four positioning blocks 400 are arranged at equal intervals along the circumference of the outer casing 100. In this way, omnidirectional positioning is achieved.

[0048] In step 3), the bottom of the lower section abuts against the bottom of the annular groove 11. This ensures the overall structure is stable.

[0049] In step 3), the top of the upper section extends above the outer casing 100. In this way, the top of the upper section is connected to the drive structure.

[0050] In step 4), during the extraction of the outer casing 100, the crushed sand 500 on the bare rock 10 is automatically added to the upper and lower annular cavities under the impact of seawater, filling the upper and lower annular cavities with the crushed sand 500, and the crushed sand 500 in the upper and lower annular cavities is compacted. In this way, the inner casing 300 is effectively reinforced, ensuring that it does not deviate during normal drilling.

[0051] In this embodiment, refer to Figure 5 The figure shown is a partial cross-sectional view of the bottom of the inner casing when it abuts against the annular groove 11, wherein the wall thickness of the inner casing is L;

[0052] The bottom of the lower section has a bottom surface, the inner side of the bottom surface has a horizontally arranged horizontal surface 310, the outer side of the bottom surface has an inclined surface 320, the lower end of the inclined surface 320 is connected to the outer periphery of the horizontal surface 310, and the upper end of the inclined surface 320 is inclined upward and penetrates the outer periphery of the lower section.

[0053] Multiple horizontal bars 330 are provided on the inclined surface 320. The multiple horizontal bars 330 are spaced around the circumference of the inclined surface 320. Along the axial direction of the inner sleeve 300, adjacent horizontal bars 330 are arranged in a staggered manner. The inner end of the horizontal bar 330 is connected to the inclined surface 320, and the outer end of the horizontal bar 330 extends outward and has a transverse gap with the inner sidewall of the annular groove 11.

[0054] In step 3), after the lower section abuts against the bottom of the annular groove 11, the horizontal surface 310 abuts against the bottom of the annular groove 11, and the inclined surface 320 is arranged upwards away from the bottom of the annular groove 11. The inclined surface 320 and the bottom of the annular groove 11 enclose a triangular annular cavity 321, and multiple horizontal strips 330 are formed in the triangular annular cavity 321. During the filling of the lower and upper annular cavities with crushed sand 500, the crushed sand 500 fills the triangular annular cavity 321 and wraps around the horizontal strips 330. In this way, the friction between the inclined surface 320, the horizontal strips 330 and the crushed sand 500 enhances the stability of the inner casing 300, ensuring that the inner casing 300 does not shift or leak grout.

[0055] The horizontal surface 310 is concave upwards, forming a concave region 311 with a ring arrangement and an open bottom. The concave region 311 is arranged around the lower section in a circumferential manner. A notch 312 is formed on the outer side of the horizontal surface 310, and the triangular ring cavity 321 is connected to the concave region 311 through the notch 312.

[0056] During the filling of the lower and upper annular cavities with crushed sand 500, as the crushed sand 500 is filled into the lower annular cavity, it enters the recessed area 311 through the notch 312 and completely fills the recessed area 311. This further enhances the connection strength between the sand layer formed by the crushed sand 500 and the inner casing 300, ensuring that the inner casing 300 does not shift or leak grout.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed marine rock, characterized in that... Includes the following steps: 1) The outer casing is lowered into the seawater, with the bottom of the outer casing abutting against the top of the bare rock, and the outer casing encloses and forms the outer casing space; 2) Using a rotary drill bit to cut the bare rock downwards, an annular groove is formed in the bare rock, and a rock column is formed in the bare rock, with the annular groove surrounding the outer periphery of the rock column; 3) An inner protective cylinder is lowered into the outer cylinder space. The lower part of the inner protective cylinder is embedded in the annular groove to form a lower section. The outer side wall of the lower section and the inner side wall of the annular groove have a lower annular cavity. The upper part of the inner protective cylinder is exposed in the outer cylinder space to form an upper section. The outer side wall of the upper section and the inner side wall of the outer protective cylinder have an upper annular cavity. 4) Pull out the outer protective sleeve; In step 1), after the bottom of the outer casing abuts against the top of the bare rock, the outer casing is temporarily fixed while maintaining a vertical position. In step 1), before lowering the outer casing, a special drill bit is used to drill and clean the bare rock. In step 1), before lowering the outer casing, a rotary drilling rig is used to clear the backfill on the bare rock. In step 4), before pulling out the outer casing, crushed sand is filled into the lower annular cavity and the upper annular cavity; The bare rock has crushed sand. In step 4), during the process of pulling out the outer casing, the crushed sand on the bare rock is automatically added into the upper and lower annular cavities under the impact of seawater, filling the upper and lower annular cavities with crushed sand, and the crushed sand in the upper and lower annular cavities is in a compacted state. The bottom of the lower section has a bottom surface, the inner side of the bottom surface has a horizontally arranged horizontal surface, the outer side of the bottom surface has an inclined surface, the lower end of the inclined surface is connected to the outer periphery of the horizontal surface, and the upper end of the inclined surface is inclined upward and penetrates the outer periphery of the lower section. The inclined surface is provided with a plurality of horizontal strips, which are spaced around the circumference of the inclined surface. Along the axial direction of the inner protective cylinder, adjacent horizontal strips are arranged in a staggered manner. The inner end of the horizontal strip is connected to the inclined surface, and the outer end of the horizontal strip extends outward and has a transverse gap with the inner sidewall of the annular groove. In step 3), after the lower section abuts against the bottom of the annular groove, the horizontal surface abuts against the bottom of the annular groove, and the inclined surface is arranged upwards away from the bottom of the annular groove. The inclined surface and the bottom of the annular groove enclose a triangular annular cavity, and multiple horizontal strips are formed in the triangular annular cavity. During the process of filling the lower annular cavity and the upper annular cavity with crushed sand, the crushed sand fills the triangular annular cavity and wraps around the horizontal strips. The horizontal plane is recessed upwards, forming a ring-shaped recessed area with an open bottom. The recessed area is arranged around the lower section in a circumferential direction. A notch is formed on the outer side of the horizontal plane, and the triangular ring cavity communicates with the recessed area through the notch. During the process of filling the lower and upper annular cavities with crushed sand, the crushed sand enters the recessed area through the notch and fills the recessed area completely.

2. The construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas as described in claim 1, characterized in that... The inner wall of the outer casing is provided with a plurality of positioning blocks, which are arranged at intervals along the circumference of the outer casing; in step 3), during the process of lowering the inner casing into the outer casing space, the positioning blocks abut against the outer wall of the inner casing.

3. The construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas as described in claim 2, characterized in that... In step 3), multiple positioning blocks are set according to the deviation between the center of the outer casing and the center of the pile hole, so that after the multiple positioning blocks abut against the outer wall of the inner casing, the center of the inner casing is aligned with the center of the pile hole.

4. The construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas as described in claim 3, characterized in that... In step 3), four positioning blocks are provided on the inner sidewall of the outer casing, and the four positioning blocks are arranged at equal intervals along the circumference of the outer casing.

5. The construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas as described in claim 1, characterized in that... In step 3), the bottom of the lower section abuts against the bottom of the annular groove.

6. The construction method for embedding and burying outer and inner casings of large-diameter rotary drilling piles in exposed rock in marine areas as described in claim 1, characterized in that... In step 3), the top of the upper section extends above the outer casing.

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