Equal-strength design and construction method applied to offshore large-diameter drilled pile

Abstract

The invention provides an equal-strength design construction method applied to an offshore large-diameter drilled pile. The equal-strength design construction method comprises the following steps that S10, a steel casing guide frame, a pile splicing platform and a guide adjusting structure are arranged; s20, the equal-strength drilling pile is drilled to form a hole; s30, the guide steel casing and the equal-strength bored pile steel casing are lowered through a floating crane; s40, a reinforcement cage is lowered through a floating crane; and S50, underwater concrete pouring is conducted. According to the method, smooth construction of the bored pile is achieved through the equal-strength design, on the premise that the structural strength of the steel casing is guaranteed, the working efficiency is improved, the engineering cost is saved, the popularization value is large, and the social benefit is good.

Description

Technical Field

[0001] The present invention belongs to the field of offshore bridge construction, and in particular relates to a construction method for equal-strength design of large-diameter bored piles in the sea. Background Art

[0002] Most of the large offshore bridges adopt group pile foundations. During the driving process of steel casing, due to the possible encounter of boulders or other historical legacy construction wastes, phenomena such as deformation and inclination of the steel casing may occur, resulting in the inability to drill and form holes for the bored piles. Since the steel casing is driven too deep, reaching hundreds of meters below the sea surface, if the steel casing is to be processed, the engineering quantity is huge or workers are unable to implement it. Summary of the Invention

[0003] In view of this, the present invention aims to propose a construction method for equal-strength design of large-diameter bored piles in the sea, so as to solve the construction problem that the bored piles cannot be drilled and formed due to boulders in the sea or other historical legacy construction wastes.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A construction method for equal-strength design of large-diameter bored piles in the sea includes the following steps:

[0006] S10: Arrange a steel casing guide frame and a pile splicing platform, and set a guide adjustment structure in the guide frame to ensure the vertical lowering of the guide steel casing;

[0007] S20: Drill and form a hole for the equal-strength bored pile;

[0008] First, use a hydraulic drill to drill an installation hole corresponding to the guide steel casing on the seabed, and then replace the drill bit to drill an installation hole corresponding to the steel casing of the equal-strength bored pile from the bottom of the installation hole;

[0009] S30: Lower the guide steel casing and the steel casing of the equal-strength bored pile by a floating crane;

[0010] First, lower the guide steel casing, and then lower the steel casing of the equal-strength bored pile;

[0011] S40: Lower the steel reinforcement cage by a floating crane;

[0012] First, lower the steel reinforcement cage corresponding to the guide steel casing, and then lower the steel reinforcement cage corresponding to the steel casing of the equal-strength bored pile;

[0013] S50: Underwater concrete pouring;

[0014] First, pour concrete into the steel casing of the equal-strength bored pile, and then pour concrete into the guide steel casing to complete the construction of the bored pile.

[0015] Further, in step S40, the steel reinforcement cage is lowered in segments in sequence. A number of U-shaped retaining rings with openings facing downward are evenly arranged in the circumferential direction at the upper part of each segment of the steel reinforcement cage. The segments of the steel reinforcement cage are hung on the support frame of the floating ship through the U-shaped retaining rings.

[0016] The U-shaped retaining rings are welded to the segments of the steel reinforcement cage.

[0017] Further, in step S30, the top of the equal-strength bored pile steel casing is flush with the top end of the guide steel casing.

[0018] Compared with the prior art, the equal-strength design and construction method for large-diameter bored piles in the sea according to the present invention has the following advantages:

[0019] For the construction of the group pile foundation of large-scale bridges in the sea, in the process of inserting and driving the steel casing, when encountering boulders or other situations that cause the deformation of the steel casing, the method of the present invention realizes the smooth construction of the bored pile by using the equal-strength design; on the premise of ensuring the structural strength of the steel casing, the working efficiency is improved, the project cost is saved, and it has great popularization value and good social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 is the construction state diagram corresponding to step S20 in this construction method;

[0022] Figure 2 is the plan view of the guide frame and the guide adjustment structure in this embodiment

[0023] Figure 3 is the construction state diagram corresponding to step S30 in this construction method;

[0024] Figure 4 is the plan view of the U-shaped retaining ring device in this embodiment;

[0025] Figure 5 is the elevation view of the U-shaped retaining ring device in this embodiment;

[0026] Figure 6 is the construction state diagram corresponding to step S40 in this construction method;

[0027] Figure 7 is the construction state diagram corresponding to step S50 in this construction method.

[0028] Description of the reference numerals:

[0029] 1. Guide steel casing; 2. Equal-strength bored pile steel casing; 3. Steel reinforcement cage; 4. Concrete; 5. Hydraulic drill; 6. Installation hole; 7. Floating crane; 8. Guide frame; 9. Guide adjustment structure; 10. U-shaped snap ring. Detailed implementation mode

[0030] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0033] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0034] A construction method for equal-strength design of large-diameter bored piles in the sea includes the following steps:

[0035] S10: Arrange the steel casing guide frame and the pile splicing platform, and set a guide adjustment structure 9 in the guide frame to ensure the vertical lowering of the guide steel casing;

[0036] The specific structures of the guide frame 8 and the guide adjustment structure 9 are as Figure 2 shown, wherein the guide frame 8 is a square frame structure, and two guide adjustment structures 9 are arranged opposite to each other and are respectively arranged at two right-angle positions opposite to the guide frame 8; the guide adjustment structure 9 adopts the existing guide structure for lowering the steel casing and will not be elaborated here;

[0037] S20: Drilling and forming holes for equal-strength bored piles;

[0038] As Figure 1 shown, use a hydraulic drill rig 5 to first drill an installation hole 6 corresponding to the guide steel casing 1 on the seabed, and then replace the drill bit to drill an installation hole 6 corresponding to the equal-strength bored pile steel casing 2 from the bottom of the installation hole;

[0039] S30: Lower the guide steel casing and the equal-strength bored pile steel casing by a floating crane;

[0040] As Figure 3 shown, use a floating crane 7 to first lower the guide steel casing 1. After the guide steel casing 1 is arranged in its corresponding installation hole 6, then lower the equal-strength bored pile steel casing 2 by the floating crane 7. After the equal-strength bored pile steel casing 2 is lowered to the corresponding installation hole 6, the preferred lowering height of the equal-strength bored pile steel casing 2 is to ensure that its top is flush with the top of the guide steel casing. At this time, the equal-strength bored pile steel casing 2 is sleeved inside the guide steel casing 1, and the insertion depth of the bottom end of the equal-strength bored pile steel casing 2 into the seabed is greater than the insertion depth of the guide steel casing 1;

[0041] S40: Lower the steel reinforcement cage by a floating crane;

[0042] As Figure 6 shown, use the floating crane 7 to first lower the steel reinforcement cage 3 corresponding to the guide steel casing, and then lower the steel reinforcement cage 3 corresponding to the equal-strength bored pile steel casing;

[0043] The steel reinforcement cage 3 corresponding to the guide steel casing and the steel reinforcement cage 3 corresponding to the equal-strength bored pile steel casing are both lowered in a segmented manner. The steel reinforcement cage is lowered in segments sequentially. A number of U-shaped snap rings 10 with openings facing downwards are evenly arranged in the circumferential direction at the bottom of each segment of the steel reinforcement cage 3. The U-shaped snap rings 10 are welded to the steel reinforcement cage segment. As Figure 4 、 Figure 5 shown, before construction, the steel reinforcement cage segment is hung on the support frame of the floating crane through the U-shaped snap rings 10. During the construction of lowering the steel reinforcement cage 3, the floating crane lowers the steel reinforcement cage segments sequentially;

[0044] S50: Underwater concrete pouring;

[0045] As Figure 7 shown, first pour concrete 4 into the equal-strength bored pile steel casing. After vibrating the poured concrete, pour concrete 4 into the guide steel casing. After the concrete 4 sets, the construction of the bored pile is completed.

[0046] For the construction method described in the present invention, aiming at the construction situation of the group pile foundation of large-scale offshore bridges, during the process of driving the steel casing, when encountering boulders or other situations that cause the steel casing to deform, the equal-strength design is used to achieve the smooth construction of offshore bored piles and ensure the construction quality.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A strong design construction method for large diameter bored piles at sea, characterized by: The following steps are involved: S10: Lay out the steel casing guide frame and the pile connection platform, and set a guide adjustment structure on the guide frame to ensure the vertical lowering of the guide steel casing; S20: Equal strength bored piles are drilled into holes; First, use a hydraulic drill to drill a mounting hole corresponding to the guide steel casing on the seabed, then replace the drill bit to drill a mounting hole corresponding to the equal strength bored pile steel casing from the bottom of the mounting hole; S30: lowering the guide steel casing and the equal-strength bored pile steel casing by means of a floating crane; first lowering the guide steel casing, and then lowering the equal-strength bored pile steel casing; S40: lowering the steel cage by floating crane; First, lower the steel cage corresponding to the guide steel casing, and then lower the steel cage corresponding to the equal-strength bored pile steel casing; S50: Underwater concrete pouring; First, pour concrete into the steel casing of the equal-strength bored pile, and then pour concrete into the guide steel casing to complete the bored pile construction.

2. A strong design construction method for large diameter bored piles at sea according to claim 1, characterized in that: In step S40, the steel cage is lowered in sections in sequence, and a number of U-shaped clamps with openings facing downwards are evenly arranged in the circumferential direction of the upper part of each steel cage section, and the steel cage sections are hung on the support frame of the floating vessel through the U-shaped clamps.

3. A strong design construction method for large diameter bored piles at sea according to claim 2, characterized in that: The U-shaped clamping ring is welded to the steel cage section.

4. A strong design construction method for large diameter bored piles at sea according to claim 1, characterized in that: In step S30, the top of the equal-strength bored pile steel casing is flush with the top of the guide steel casing.

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