JPS60119817A - Construction work of structure - Google Patents

Abstract

PURPOSE:To construct structures having structurally high reliability by a method in which the free long portion of an anchor whose lower part is fixed to the ground is tensely introduced into and fixed to a structure on the ground's surface. CONSTITUTION:An earth anchor A is penetrated into an excavated pit 2 in the seabed ground 1. The upper free long portion 3a3 projected from the ground 1 is introduced into a jacket structure B, and a grout 7 is injected under pressure into the structure B and the pit 2 to fix the lower end 3a1 of the anchor A to the pit 2. The upper free long portion 3a3 of the twist steel wire 3 of the anchor A is tensed by a jack and fixed through a wedge 9 to the hole of the anchor head 8. The tension force of the head of the anchor A is transmitted as a compression force to the ground 1 through the head 8 and a distribution plate from the structure B. Tensile load to be applied to the anchor A is also transmitted to the grout 7 and the ground 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventional earth anchors can be used either temporarily or permanently. The main example of a temporary anchor is a mountain anchor for underground open cuts.

It is also used as reaction force anchors for traction, anchors for construction crane foundations, suspension anchors for various steel bridges, etc.

Examples of the use of anchors for permanent structures include vertical anchors for buildings where tensile forces occur, various steel towers, suspension bridges, and ground protection works.

The present invention utilizes the characteristics of the earth anchor.

This was proposed with the aim of providing an improved construction method for constructing structures with high structural reliability in locations such as coastal areas where large horizontal forces act and where it is impossible to work on the ground surface. , a method for constructing a structure, characterized in that a free length part of an anchor material whose lower base is anchored in the ground is introduced into a structure on the ground, tensioned, and anchored to the structure. It is.

In the present invention, as described above, the free length part of the anchor material whose lower bottom part is anchored in the ground is introduced into the structure on the ground, and the free length part is tensioned to secure the anchor material to the structure. Since the anchor material and the structure are integrated, the tension of the anchor material and the position where anchoring work can be changed can be changed up to the height of one novel consisting of the ground surface. .

This is advantageous for constructing structures such as coastal areas, where breaking waves occur constantly, making it difficult to work on the ground surface, and where large horizontal forces act, resulting in large pulling forces.

In addition, since the anchor material is anchored to the structure on the base by tensioning it, the force of introduction of the anchor material increases the frictional resistance between the structure and the base, making the structure lighter. Great sliding resistance can be obtained even when the

Furthermore, the present invention has many advantages, such as being able to perform construction using relatively small-scale construction machinery, reducing construction costs and shortening the construction period.

Hereinafter, an illustrated embodiment in which the present invention is applied to installing a jacket strafe, which is a structure supporting a ziphon pipe extended from the coast to offshore, on a seabed bedrock will be described.

An earth anchor is inserted into a drill hole (2) constructed by poling into the seabed ground (1) from above the sea surface.

Earth anchor (Al is the tip anchoring part (3) of the steel stranded wire (3)
The outer periphery of the free length portions (3α2) (3α3) excluding α1) is coated with grease, bituminous material, etc., so that they can be expanded in the grout, and the anchoring portion (3a1) and the rock A protective tube (
4) is wrapped concentrically to prevent seawater from corroding the stranded steel wire. Further, in the anchoring part (3αl), a grout (5) is previously split horizontally between the anchoring part (3α1) and the maintenance pipe (4) above the ground.

In the figure (6) is the mortar (
5) is the leakage prevention lid piece.

After inserting the earth anchor (Al) into the bent hole (2) of the ground (1), the upper free length part (3α3) protruding from the top of the rock (1) is inserted into the ground (1). At the same time, grout is introduced into the jacket structure (B) and into the excavation hole (2) using a grout pump. Anchor in the excavated hole (2) in the ground (1).

Then the earth anchor (steel strands in Al (3)
The upper free length part (3α3) of is pivoted and tensioned with a hydraulic jack, and the anchor spatula)' (8) is wedged into the PC steel stranded wire insertion hole through the wedge (9), and the earth anchor tA) is The tension force on the head of the anchor spatula)' (8) and the bearing plate (10
) as a compressive force through the jacket struture (El
It is transmitted from to the bedrock (1). On the other hand, the tensile load acting on the earth anchor is transmitted to the surrounding grout (force) and the ground (1). It is the base of

Therefore, the above force is balanced between the side surface of the base of the jacket strafe (B) and the surface of the ground (1). For this reason, it is desirable that the ground (1) be highly rigid, such as rock.

As the design load of the jacket struf- ture (B), the required initial introduction force of the earth anchor is Pt, the maximum compressive force acting on the jacket struf- ture (B) is R, and the maximum tension acting on the PC steel strand of the earth anchor. If Pt2 is set as follows, pt=α·Wt R=Pt+α·Wr Pi2=Pt+β·Wt.

Here, Wt: Maximum external force on the pulling side Wr: Maximum external force on the pushing side α = K1 / Kl + K2 β = K2 / Kl Figure 2 Pt2. The relationship between R9R1 and the external force W is shown, and as can be seen from the figure, the jacket strafe (B) has a load (the initial tension P4 of the earth anchor (At) plus the external force).
If it is designed to withstand Pi+αwr), other design conditions can be established using the same procedure as for ordinary earth anchors.

In the illustrated embodiment, the upper free length (3α3) of the PC steel stranded wire (3) of the earth anchor (earth anchor) is introduced into the jacket struf- ture (B), tensioned, and anchored. A) and the jacket strafe (foundation) are integrated, and it is possible to change the position where work such as tensioning the PC copper stranded wire is done up to the level of the ground (1). This is advantageous for structures with structures where it is difficult to work on the ground, such as in coastal areas, where very large horizontal forces act, and the resulting pull-out force is large.In addition, the introduction force of the earth anchor allows the jacket straft to be The frictional resistance between Bl and the ground (1) increases,
Although the structure is lightweight, it provides high sliding resistance.

Furthermore, the process of poling the seabed, inserting the earth anchor, injecting grout, and tensioning the PC steel strands is all carried out on the sea surface, but the construction equipment used is relatively small.
It is highly economical and shortens the construction period.

The present invention has been put into practice! 11 has been described, but the present invention is of course not limited to such an embodiment, and various modifications of the configuration δ1 can be made within the scope of the invention of 411.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing the implementation status of one embodiment of the horizontal construction method for structures according to the present invention, and Fig. 2 shows the relationship between external force, P'C copper stranded wire tension of the earth anchor, and force within the girder structure. This is a chart showing the relationship. Prisoner...Earth anchor, (Bl...Jacket strafe, (1)...Ground, (3)...PC steel stranded wire, (3α)...Anchoring part, (3b)( 3C)... Free length part, (7)... Grout, (8)... Anchor head, 10)... Bearing plate No. 1M Outside: Push No. 20 5(w) Continuation of page 1 @ Inventor Motoetsu Ishii 4-6-2 Kannon Shinmachi, Nishi-ku, Hiroshima City, Mitsubishi Heavy Industries, Ltd. Hiroshima Shipyard

Claims (1)

[Claims] A method for constructing a structure, characterized in that a free length part of an anchor material whose lower base is anchored in the ground is introduced into a structure on the ground, tensioned, and anchored to the structure.