JPS63304825A - Steel master pile for prestressed sheathing - Google Patents

Abstract

PURPOSE:To cut down the cost of construction work by a method in which plates projecting backwards are attached to the upper and lower ends of a steel master pile, and PC wire is laid between both plates and tensed to introduce a prestress into the master pile. CONSTITUTION:Steel wire couplers 13 are provided for the left and right sides of a horizontal plate 11, and a pin 14 is pierced through a vertical plate 12. A PC steel wire 15 is laid between the pin 14 and the couplers 13 and tensed by a jack, and the couplers 13 are worked to introduced a prestress. Pits are excavated at an interval, a master pile 1 is dropped into the pits by positioning the wire 15 backwards, and excavation is made. A sheathing board 2 is inserted and supported on the pile 1. A wailing material 3 and shore strut 4 are assembled through back-filled concrete 6 on a bracket 5 attached to the back of the pile 1 for timbering work.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a steel parent pile for prestressed piles.

``Problems to be solved by the prior art and the invention'' A pile stop using a steel main pile such as H steel is already well known.

In order to secure this peak, normally, as shown in Figure 4,
Vertical holes are excavated at appropriate intervals using an auger machine, soil auger machine, etc., and the main piles (steel etc.) are dropped in (■). Next, the roots are cut and the weir plate is installed. 2... are inserted and supported by the main pile, and appropriate uprights 3... and cut beams 4... are assembled in the middle of the main pile to provide shoring (■) .

In this case, as the root pruning progresses, the main stake l...
As shown in FIG. 5, the bending moment M is generated in stages. In other words, a bending moment M is generated that is slightly forward at the top, mostly backward, and reaches its maximum value (M-MAX) at the bottom.

Therefore, the maximum value (M・MA
It requires an even larger yield strength R than X), requires a steel material with a considerably larger cross-sectional shape, and is extremely uneconomical.

The present invention seeks to eliminate such conventional drawbacks.

"Means for Solving the Problems" The present invention provides a method for attaching plates that protrude to the rear at the upper and lower ends of the steel main pile, and installing and tensioning a PC steel wire between the two plates. This is made by introducing prestress into the parent pile.

``Operation'' The structure is as described above, and when securing piles, it is sufficient to position the PC steel wire at the rear and use it in the same way as before. However, the prestress caused by the PC steel wire behind moves the bending moment forward. As a result, the parent pile can be made reasonably small and the intended purpose can be achieved.

"Example" 1 to 3 show embodiments of the invention.

The illustrated one is a main pile 1 made of 11 steel for use as a heap, and has a horizontal plate 11 at the upper end that protrudes to the rear, and a vertical plate 12 at the lower end that protrudes to the rear. , two steel wire fastening means on the left and right 13.1
3, a pin 14 is fixed through the vertical plate 12, and a steel wire fastening means 13 is attached to the left end of the pin 14 and the left side of the pin 14.
The PC steel Ij115.15 is stretched between the right end of the pin 14 and the right steel wire fastening means 13, and tensioned at the upper end by jacking or the like to tighten the steel wire fastening means 13.1.
3 and introduce prestress. The degree of this prestress is selected in consideration of the bending moment that will occur in the main pile l.

In order to stop the piles, vertical holes are drilled at appropriate intervals using an auger machine, a soil hoger machine, etc., and the above-mentioned parent piles 1... Then, cut the roots, insert the weir plates 2 and support them on the main piles 1, and
A bracket 5.5 is attached to the back of the middle part of the parent pile at a suitable location, and on the bracket, the raised material 3... and the cut beam 4... are installed through the backfill concrete 6.6, and the support is carry out construction.

In this case, the bending moment M generated in the parent pile 1 becomes uniformly distributed forward as shown in Fig. 3 I before root cutting, and finally, as shown in Fig. 3 I As shown in the figure, the PC in the background has the same distribution as before! I
It is in a state where it is pushed forward by the prestress of the I line 15.15.

This extrusion transfer! 1JIi may be set such that the integral value of the compression a and the negative range is equal, and a prestress may be introduced to match this.

Note that the number of PC steel wires is not limited to two, but may be any number suitable for the prestress required for calculation, and the same applies to the thickness, etc.

"Effects of the Invention" According to the present invention, the parent pile can be used mechanically and rationally, so the cross-sectional shape of the parent pile can be made small, and the number of uprights and cut beams can be reduced, so that The amount can be significantly reduced, costs can be reduced, and resources can be saved.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, in which FIG. 1 is a side view in use, FIG. 2 is a rear view, and FIG. 3 is a 1. I
I shows a bending moment diagram, FIGS. 4 and 5 show a conventional example, and FIG. II is a process explanatory diagram, and FIG. 5 is a bending moment diagram. l... Main stake 2... Weir board 3... Raising material 4... Cutout 5... Bracket 6...
・Backfill concrete 11...horizontal play) 12
...Vertical plate 13... Steel wire fastening means 14...
・Pin 15...PC steel wire patent applicant Takenaka Construction Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 11... Vinyl glass I II

Claims (1)

[Claims] This plate is characterized in that plates protruding backward are attached to the upper and lower ends of the steel parent pile, and prestress is introduced into the steel parent pile by installing and tensioning a PC steel wire between both plates. Steel main pile for stress piles.