JPH1077615A - Base isolated pier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut off transmission of ground vibration to the upper part of a pier and apparatuses, to reduce a cost through reduction of the number piles, and to shorten a term of works by a method wherein the upper parts of the lower parts of pieces comprising a plurality of piles are coupled together by a coupling member for integrally formation, a plurality of base isolation shoes are arranged on the coupling member, and the upper part of the pier is arranged thereon. SOLUTION: A lower part A of a pier comprises a plurality of straight piles 1a and oblique piles 1b embedded in a seat bottom ground and the upper parts thereof are coupled together by coupling beams 2 for integral formation. A plurality of base isolation shoes 3 formed of lamination rubber are arranged in a dispersed state on the coupling beam 2, and an upper slab 4 built by precast or site construction and forming a pier upper part B is built thereon. Thus, transmission of horizontal ground vibration exerted on the pier lower part A during an earthquake is cut off by the base insulation shoes 3 and an inertial force is prevented from generation at an upper part B. This constitution remarkably reduces a horizontal force generated at the piles 1a and 1b, reduces the sizes of the piles 1a and 1b and the number of the piles, decreases a cost, and shorten a term of works.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pier structure as a port / marine structure having a seismic isolation function against an earthquake.

[0002]

2. Description of the Related Art Conventional seismic design of harbors and offshore structures such as piers has been carried out by the static seismic intensity method. This is done by increasing the rigidity of the steel or by using a steel material for the upper structure to reduce the weight and reduce the inertial force.

[0003]

Since the January 1995 Hyogoken-Nanbu Earthquake, the need for improved seismic performance of harbors and marine structures has been increasing. Among these, the structure (pile size and arrangement) of the horizontal pier and the dolphin pier for cargo handling is determined by seismic force.

[0004] In the conventional design method, the design seismic intensity of such a pier is 0.25 at the maximum, and it is not possible to cope with a large direct earthquake.

The present invention has been made under such a background. The seismic isolation structure blocks transmission of seismic motion to the pier superstructure and equipment, thereby eliminating the burden on the piles and reducing the size and number of piles. The cost and the construction period are reduced by the reduction.

[0006]

The seismic isolation pier of the present invention is:
The upper part of the pier substructure consisting of a plurality of piles is connected and integrated by a connecting member, a plurality of seismic isolation shoes are installed on the connecting member, and the pier superstructure is provided on the seismic isolation shoe.

[0007] That is, the upper part of the pier substructure consisting of straight piles, slanted piles and the like is connected by a connecting girder or the like as a connecting member, and these are integrated. On top of this, seismic isolation shoes made of laminated rubber etc. will be installed, and a pier superstructure will be installed by installing or constructing a precast or on-site superstructure slab.

The connecting member is not limited to a spar, but may be, for example, a plate-shaped member. As the seismic isolation structure itself, various types used in conventional seismic isolation buildings can be used in addition to those using laminated rubber, and various energy absorbing dampers can be used together as needed.

[0009]

FIG. 1 shows an embodiment of the present invention, in which (a) is a plan view and (b) is a front view.

In the illustrated embodiment, the pier substructure A
Consists of a plurality of straight piles 1a and slant piles 1b rooted in the seabed ground, and their upper ends are connected and integrated by a connecting girder 2.

A plurality of seismic isolation shoes 3 made of laminated rubber or the like are dispersedly arranged on the connecting girder 2, and a superstructure slab 4 constituting a pier superstructure B is installed thereon. The superstructure slab 4 may be made of precast or cast in place.

When there is no seismic isolation layer due to the seismic isolation shoes 3, etc., the seismic motion is transmitted from the piles 1a, 1b of the pier lower part A to the upper part B during an earthquake, and conversely, the upper part B ( Large horizontal force acts in the form of inertial force. Therefore, the stakes 1a and 1b are required to have sufficient rigidity and number to withstand the horizontal force.

However, in the case of the present invention, the transmission of horizontal seismic motion acting on the pier lower part A during an earthquake is interrupted by the seismic isolation shoes 3, so that no inertial force is generated in the upper part B and the piles 1a,
The horizontal force generated in 1b is greatly reduced, and as a result, the size and the number of piles 1a and 1b can be reduced.

[0014]

According to the seismic isolation device, seismic motion from the ground, which should be transmitted to the superstructure via the pile, is cut off, and the inertia force of the superstructure is not generated. As a result, the horizontal force generated on the pile is greatly reduced, and the size and the number of piles can be reduced, leading to a significant cost reduction and a shortened construction period.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, wherein (a) is a plan view and (b) is a front view.

[Explanation of symbols]

1a: straight pile, 1b: slanted pile, 2: coupling girder, 3: seismic isolation shoe, 4
… Superstructure slab

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takuya Sato Kashima Construction Co., Ltd. 1-2-7 Moto-Akasaka, Minato-ku, Tokyo

Claims (1)

[Claims] 1. An upper part of a pier substructure composed of a plurality of piles is connected and integrated by a connecting member, a plurality of seismic isolation shoes are installed on the connecting member, and a pier superstructure is mounted on the seismic isolating shoe. A seismic isolation pier that has been established.