JP2016217107A - Steel pipe diameter change ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe diameter change ring capable of welding a steel pipe such as a steel pipe pile or a ground reinforcement pile body with a selected steel pipe of a different size while reducing the cost for the steel pipe pile and ground reinforcement pile body.SOLUTION: A steel pipe diameter change ring R21 is used for welding Y21, Y22 a large diameter steel pipe P22 and a small diameter steel pipe P21. The steel pipe diameter change ring R21 has a large diameter end for being welded with a large diameter steel pipe, and a small diameter end for being welded with a small diameter steel pipe selected from two or more different sizes. The steel pipe diameter change ring R21 has a guide rib for allowing centering between the large diameter steel pipe and the small diameter steel pipe without depending on the thickness of the steel pipe.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steel pipe diameter conversion ring that is used when a steel pipe used as a steel pipe pile or a pile-shaped ground reinforcement body is desired to change the steel pipe diameter in the longitudinal direction.

  In order to reinforce the soft ground, steel pipes are used as steel pipe piles and pile-shaped ground reinforcement bodies. It is known that the larger the steel pipe diameter is, the more effective it is for the ultimate vertical bearing capacity of the pile and the limit horizontal resistance force of the pile head, but the steel pipe cost increases by increasing the pile diameter. It was an important issue to increase the ultimate vertical bearing force and the limit horizontal resistance force while maintaining the steel pipe cost.

  The ultimate bearing force at the tip of the steel pipe pile and the pile-shaped ground reinforcement is determined by the product of the effective area of the tip and the average N value in the range of 1D below the tip and 4D above. (D: Diameter of pile and pile-shaped ground reinforcement steel pipe) Further, it is known that the limit horizontal resistance force acts advantageously if the section modulus of the steel pipe is large.

  However, several methods have been proposed to change the diameter of steel pipes used as steel pipe piles or pile-shaped ground reinforcements, but a method of combining multiple pile diameters and wall thicknesses with a single component at low cost. Has not been established yet.

JP 2000-73365 A JP 2003-105755 A JP 2008-25156 A

  The object of the present invention is to make it possible to select a steel pipe used as a steel pipe pile or pile-shaped ground reinforcement body from the optimum steel pipe diameter and thickness near the tip and pile head. The aim is to provide a steel pipe diameter conversion ring that can be easily aligned with the shaft to reduce material costs, and to provide a cost-effective steel pipe pile and pile-shaped ground reinforcement.

  The steel pipe diameter conversion ring according to the present invention has a structure capable of welding and connecting steel pipes having different outer diameters and wall thicknesses used in the longitudinal direction. This steel pipe diameter conversion ring is a structure that can weld steel pipes of different diameters to both ends of the ring, and since the mounting direction is not constrained in the longitudinal direction, the change from large diameter steel pipe to small diameter steel pipe and small diameter The structure can be easily changed from a steel pipe to a large-diameter steel pipe. Further, in changing the steel pipe, a plurality of small-diameter steel pipes can be selected on a single steel pipe diameter conversion ring, and there is no restriction on the thickness of the steel pipe.

  The steel pipe diameter conversion ring according to the present invention has a structure capable of welding and connecting steel pipes having different outer diameters and thicknesses suitable for the purpose in the longitudinal direction. For example, as shown in FIG. 2, a steel pipe having a large outer diameter, a large wall thickness, and a large section modulus is used in the vicinity of the pile head where a horizontal force or bending moment acts from the superstructure, and the 4D (D : Steel pipe diameter or tip edge diameter) or more, use a steel pipe applied to the tip edge diameter, and use a steel pipe with a small outer diameter in other parts. In addition, it is possible to select a plurality of small-diameter steel pipes on one steel pipe diameter conversion ring, and there is no restriction on the thickness of the steel pipe, so that it is possible to reduce the material cost of steel pipes used as steel pipe piles and pile-shaped ground reinforcements.

  In addition, because there is a guide rib for centering for each wall thickness of the steel pipe used, the center axis shift between different diameter steel pipes, which often occurs when welding different diameter steel pipes, is easy to weld and shortens the construction time. Can also be planned.

The side view which welded the small diameter steel pipe and the large diameter steel pipe to the steel pipe diameter conversion ring. Sectional view of welding a small diameter steel pipe and a large diameter steel pipe to a steel pipe diameter conversion ring The side view which shows the guide rib for centering processed into the small diameter end part and large diameter end part of the steel pipe diameter conversion ring. Example of steel pipe diameter conversion ring to steel pipe pile or pile-shaped ground reinforcement.

  An embodiment using a steel pipe diameter conversion ring according to the present invention will be described with reference to the drawings.

  1 shows a steel pipe diameter conversion ring R11 welded with a steel pipe P12 having a diameter corresponding to the tip edge used as a steel pipe pile or pile-shaped ground reinforcement body to the large end of the steel pipe diameter conversion ring, and the minimum diameter of the small end. It is the side view which welded the small diameter steel pipe P11 on the guide rib for centering. 2 is a cross-sectional view of FIG. 1, wherein Y21 is a welded cross section of a small diameter steel pipe and Y22 is a welded cross section of a large diameter steel pipe.

  1 and 2 show an example in which a small-diameter steel pipe is welded to the top and a large-diameter steel pipe is welded to the bottom. However, the steel-diameter conversion ring has a function that can be used upside down. It is also possible to use by welding to the lower part. Welding is basically performed in a factory, but since it has a guide rib for centering that prevents center axis deviation, on-site welding is also possible. The steel pipe diameter conversion ring is a cast steel member having mechanical performance equivalent to that of the steel pipe used.

  FIG. 3 shows guide ribs for centering processed into a small diameter end portion and a large diameter end portion of a steel pipe diameter conversion ring. S1 is a part where a steel pipe with a minimum diameter is welded, and a guide rib is processed for each thickness of the steel pipe to be used. S2 is a part where a medium diameter steel pipe is welded, and S3 is a part where a large diameter steel pipe is welded. A guide rib corresponding to the thickness of the steel pipe used is processed.

  FIG. 4 is an overall image L1 of the steel pipe pile and the pile-shaped ground reinforcement body. The steel pipe P41 of the upper end portion L2 is a steel pipe having a sufficient section modulus to cope with the horizontal force and bending moment from the upper structure. The steel pipe diameter conversion ring R41 is welded Y41 with the large diameter end facing up. A small diameter steel pipe P42 is welded Y42 to the small diameter end portion.

  The lower end portion L3 is a part that affects the ultimate support force of the tip of the steel pipe pile or the pile-shaped ground reinforcement body. A steel pipe P43 applied to the tip edge diameter is welded Y45 to the tip edge, and the tip edge tip outer diameter of 4 is obtained. In order to reduce the material cost, welding Y44 is performed with the large-diameter end of the steel pipe diameter conversion ring R42 facing down, and the small-diameter steel pipe P42 is welded Y43 to the minimum diameter portion of the small-diameter end.

P11 Steel pipe diameter conversion ring welded small diameter steel pipe R11 Steel pipe diameter conversion ring side view P12 Steel pipe diameter conversion ring welded large diameter steel pipe D1 Small diameter steel pipe outer diameter D2 Small diameter steel pipe inner diameter D3 Large diameter steel pipe outer diameter D4 Large diameter Steel pipe inner diameter Y21 Steel pipe diameter conversion ring and small diameter steel pipe weld R21 Cross section of steel pipe diameter conversion ring Y22 Steel pipe diameter conversion ring and large diameter steel pipe weld S1 For connecting the smallest diameter steel pipe on the small diameter end of the steel pipe diameter conversion ring Centering guide rib side view S2 Centering guide rib side view for medium diameter steel pipe connection on the small diameter end side of the steel pipe diameter conversion ring Side view S3 Centering guide rib side view for large diameter steel pipe connection on the small diameter end side of the steel pipe diameter conversion ring L1 Steel pipe pile or pile shape Overall image of ground reinforcement L2 Pile head vicinity image of steel pipe pile and pile-shaped ground reinforcement L3 Tip edge vicinity image P of steel pipe pile and pile-shaped ground reinforcement body 41 Steel pipe with large section modulus near the pile head of steel pipe pile or pile-shaped ground reinforcement body P42 Small-diameter steel pipe P43 of steel pipe pile or pile-shaped ground reinforcement body Applicable diameter steel pipe Y41 steel pipe with tip edge of steel pipe pile or pile-shaped ground reinforcement body Welded part R41 welded with a large diameter steel pipe with the large diameter end of the diameter conversion ring facing upwards Example Y42 using the large diameter end of the steel pipe diameter conversion ring facing upwards With the large diameter end of the steel pipe diameter conversion ring facing upward Welded part Y43 welded with small diameter steel pipe Welded part R42 welded with small diameter steel pipe with the large diameter end of the steel pipe diameter conversion ring facing downward Y42 Example of using the large diameter end of the steel pipe diameter conversion ring downward Welded part Y45 welded to the applicable diameter steel pipe of the tip edge with the large diameter end of the ring facing downward Welded part welded to the applicable diameter steel pipe of the tip edge and the tip edge

Claims (4)

Steel pipe diameter conversion ring that can weld large diameter steel pipe and small diameter steel pipe.   The steel pipe diameter conversion ring according to claim 1, wherein two or more kinds of small diameter steel pipes can be selected and used.   The steel pipe diameter conversion ring according to claim 1 or 2, wherein the steel pipe diameter conversion ring has a welding groove that is not affected by the outer diameter and thickness of the steel pipe to be welded.   4. A centering guide rib capable of easily aligning the central axes of a large-diameter steel pipe and a small-diameter steel pipe regardless of the thickness of the steel pipe to be welded. Steel pipe diameter conversion ring as described.