Design method for full-section welding connection of steel pipe pile

Abstract

A steel pipe pile full-section welding connection design method comprises the following steps that steel pipe piles are connected through full-section welding seams, a plurality of reinforcing cover plates are adopted at the full-section welding seams for reinforcing connection, and the reinforcing cover plates are rectangular and are welded to the three faces of the steel pipe piles in a surrounding mode; and the reinforcing cover plates are symmetrically arranged up and down along the full-section weld joint and are arranged at equal intervals along the circumference of the steel pipe pile. The minimum width b of the reinforcing cover plates is obtained according to the fact that the sum B of the widths of the n reinforcing cover plates is not lower than 50% of the perimeter of the full-section weld joint of the steel pipe pile, and n is 6 or 8; the axial bearing capacity of the weld joint of the surrounding fillet on the three sides of the reinforcing cover plate is not lower than the tensile resistance of the reinforcing cover plate, the proportion alpha of the height h to the width b of the reinforcing cover plate is obtained, and then the specific size of the reinforcing cover plate is determined. The method has the advantages that normative theoretical analysis and calculation are conducted on the design of the steel pipe pile full-section welding reinforcement cover plate, the welding reinforcement quality of the steel pipe pile full-section welding reinforcement cover plate is guaranteed, good application prospects are achieved, and obvious economic benefits and social benefits can be generated.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering and relates to a design method for full-section welding connection of a steel pipe pile. Background Art

[0002] In engineering projects, we often face the situation of extending steel pipe piles. Flange bolt connection is often used for steel pipe pile connection. Flange bolt connection is reliable in force, but the structure is complex, the manufacturing and installation processes are more, and the cost is high. In order to ensure the reliability of steel pipe pile welding connection, a simple and reliable steel pipe pile full section welding connection design method is needed. Summary of the invention

[0003] The purpose of the invention is to provide a design method for full-section welding connection of steel pipe piles.

[0004] The present invention is achieved through the following technical solutions.

[0005] A method for designing full-section welded connections of steel pipe piles according to the present invention comprises the following steps:

[0006] The steel pipe pile (1) and the extended steel pipe pile (2) are connected by a full-section weld (4), and a plurality of rectangular cover plates (3) are used at the full-section weld (4) for reinforcement connection, and are welded around three sides of the steel pipe pile. The rectangular cover plates are arranged symmetrically up and down along the full-section weld and are arranged at equal intervals along the circumference of the steel pipe pile.

[0007] Assume that the diameter of the steel pipe pile is d, the thickness is t, and the perimeter of the full-section weld is S = πd; the rectangular cover is rectangular, with a height of h, a width of b, a ratio of height to width α = h / b, a thickness of t, and a number of n, where n is generally taken as 6 or 8 based on experience; the design value of the tensile strength of the rectangular cover steel is f d , weld tensile strength design value The size of the weld leg of the three-sided corner weld of the rectangular cover is h f .

[0008] In order to ensure the stress reliability of the full-section weld connection, the sum of the widths B of the n rectangular cover plates should not be less than 50% of the circumference of the full-section weld of the steel pipe pile, and the minimum width b of the rectangular cover plates is obtained.

[0009]

[0010] Based on the fact that the axial bearing capacity of the fillet welds on the three sides of the rectangular cover plate is not less than the tensile strength of the rectangular cover plate, the minimum height h of the rectangular cover plate is obtained.

[0011]

[0012] The ratio α of the height to the width of the rectangular cover can be obtained.

[0013]

[0014] The number n=6 or 8 of the rectangular cover plates is selected according to the diameter of the steel pipe piles and the construction conditions, and the size of the rectangular cover plates is then determined.

[0015] The present invention adopts full-section welding connection of steel pipe piles, that is, the cross section of the steel pipe pile is first connected by butt welding, and then a plurality of rectangular cover plates are used at the full-section weld for reinforcement connection, and welded around three sides of the steel pipe pile. This connection method can not only ensure the structural force requirements, but also ensure the reliability of the cross-section connection, and is easy to process and manufacture. In addition, the size and quantity of the rectangular cover plates directly affect the processing and manufacturing quality and installation efficiency. If the width of the rectangular cover plate is too small, the number of rectangular cover plates required will increase, the weld length will be increased, and the welding residual stress and residual deformation will be increased; if the width of the rectangular cover plate is too large, it will easily cause a large gap between the rectangular cover plate and the surface of the steel pipe pile, poor fit, and poor force coordination.

[0016] The invention has the advantages of performing standardized theoretical analysis and calculation on the design of the full-section welded rectangular cover plate of the steel pipe pile, ensuring the welding reinforcement quality thereof, having good application prospects, and being able to generate obvious economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the full-section welded rectangular cover of the steel pipe pile.

[0018] Figure 2 for Figure 1 AA cross-section shown.

[0019] Figure 3 for Figure 1 BB cross section shown.

[0020] Legend: 1- steel pipe pile; 2- extended steel pipe pile; 3- rectangular cover plate; 4- full section weld; 5- three-sided fillet weld of rectangular cover plate. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0022] See also Figure 1 to Figure 3 A design method for full-section welded connection of steel pipe piles, wherein a steel pipe pile 1 and an extended steel pipe pile 2 are connected by a full-section weld 4, and a plurality of rectangular cover plates 3 are used at the full-section weld 4 for reinforcement connection, and are welded around three sides of the steel pipe pile 1 and the extended steel pipe pile 2. The rectangular cover plates 3 are arranged symmetrically up and down along the full-section weld 4, and are arranged at equal intervals along the circumference of the steel pipe pile 1.

[0023] Example 1.

[0024] The diameter of the steel pipe pile 1 and the extended steel pipe pile 2 is d = 600mm, and the thickness is t = 16mm; the overlapping steel plate 3 is rectangular, with a height of h, a width of b, and a thickness of t = 16mm; the steel material is Q345 steel, and the steel strength design value is f d =275Mpa, the strength design value of the fillet weld when using Q345 steel Weld leg size h f =14mm.

[0025] The sum of the widths B of n rectangular cover plates should not be less than 50% of the circumference of the full-section weld of the steel pipe pile. The number of rectangular cover plates n=6 is selected based on the diameter of the steel pipe pile, the principle of axial symmetry and ease of manufacturing, and the minimum width b of the rectangular cover plates is obtained.

[0026]

[0027] Based on the fact that the axial bearing capacity of the fillet welds on the three sides of the rectangular cover plate is not less than the tensile strength of the rectangular cover plate, the minimum height h of the rectangular cover plate is obtained.

[0028]

[0029] The ratio α of the height to the width of the rectangular cover can be obtained.

[0030]

[0031] On the premise of meeting the above calculation requirements, in order to reduce the weld length of the rectangular cover plate, reduce welding residual stress and residual deformation, and at the same time to ensure the close fit between the rectangular cover plate and the steel pipe piles, the height of the rectangular cover plate is determined to be h = 250mm and the width b = 160mm.

[0032] The above is only an embodiment of the present invention, and the common sense such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A design method for full-section welding connection of steel pipe piles, characterized in that The following steps are involved: The steel pipe pile (1) and the extended steel pipe pile (2) are connected by a full-section weld (4), and a plurality of rectangular cover plates (3) are used at the full-section weld (4) for reinforcement connection, and are welded around three sides of the steel pipe pile; the rectangular cover plates are arranged symmetrically up and down along the full-section weld, and are arranged at equal intervals along the circumference of the steel pipe pile; Assume that the diameter of the steel pipe pile is d, the thickness is t, and the perimeter of the full-section weld is S = πd; the rectangular cover is rectangular, with a height of h, a width of b, a ratio of height to width α = h / b, a thickness of t, and a number of n, where n is 6 or 8; the design value of the tensile strength of the rectangular cover steel is f d , weld tensile strength design value The size of the weld leg of the three-sided corner weld of the rectangular cover is h f ; In order to ensure the reliability of the full-section weld connection, the sum of the widths B of the n rectangular cover plates should not be less than 50% of the circumference of the full-section weld of the steel pipe pile, and the minimum width b of the rectangular cover plate is obtained: According to the fact that the axial bearing capacity of the fillet welds on the three sides of the rectangular cover is not less than the tensile strength of the rectangular cover, the minimum height h of the rectangular cover is obtained: The ratio of the height to the width of the rectangular cover, α, can be obtained:

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