JPH10152822A - Precast landing bridge structure and wharf construction method using the structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and remarkably shorten the construction period especially as the recovery construction method of a disaster stricken wharf or the like, and also to absorb the level difference error caused between the foundation piles so that the influence on the rigidity or the like given to upper construction beams can be restrained. SOLUTION: In a precast landing bridge structure, foundation piles 20 are driven into the bottom of the water at prescribed pitches along the length of the landing bridge to be constructed, and precast blocks 10 as for the upper construction beams above the landing bridge of RC structure that have been previously divided along the length of the landing bridge are manufactured. In the precast block 10, sheath pipes 12 for integrating with the piles by inserting the pile heads of the foundation piles 20 at the time of erection are embedded. A level adjusting support mechanism 23 is installed on the pile head supporting part of the foundation pipe 20, so that the level difference h with regard to the reference level H of the pile head support parts of the foundation piles 20 due to the construction error or the like is absorbed, and also the support reaction of the foundation piles due to the weight of the precast block 10 after erection can be uniformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast pier structure and a pier construction method using the precast pier structure, which is particularly effective for work requiring a short period of time such as urgency.

[0002]

2. Description of the Related Art In a work requiring a short time due to urgency, it is strongly desired to shorten a construction period without being affected by sea conditions. In particular, in the case of pier construction using a pile type horizontal pier superstructure, the conventional general cast-in-place RC (reinfoced co
When the construction method is adopted, during the construction period, it will be affected by typhoons and other waves in stormy weather, and the wake waves of sailing vessels. For this reason, there is a risk in the process from the erection of the shoring work to the concrete placement, which requires a considerable construction period. In addition, labor saving of construction work is necessary due to aging of civil engineering workers.

In the 1995 Hanshin-Awaji Earthquake,
The applicant was involved in the restoration work of Kobe Port Maya Wharf. At that time, as an alternative to the conventional cast-in-place RC method, a block-type pier upper part with a length of 9.5 to 26.25 m using RC structure was installed in order to accommodate the total length of the restoration pier of 599 m. Precast block construction method was adopted. In this case, precast blocks are preliminarily manufactured in a production yard on land, and each block is erected on a foundation pile made up of steel pipe piled in along the restoration wharf. It is to connect.

[0004] Such a precast block construction method has achieved an epoch-making result of realizing a drastic reduction in the construction period. In the process of restoration work, the inventors tried to reduce the construction period and labor by pre-casting,
The length of each precast block to be the beam of the superstructure was made as long as possible. The number of foundation piles corresponding to the 50m extension of one span of the pier is 2
About 0 was considered. The foundation pile is driven from the seaside to the seabed by a vibrohammer of a barge with crane.

[0005]

When a support portion for supporting a precast block is provided at the top of the pile head of each cast foundation pile, the height difference between the support portion and the reference level is adjusted. It is almost impossible to make it ± 0, and it is necessary to expect a height difference of up to around ± 5 mm due to construction errors and the like. Due to such a difference in height of the bearing, there is a large influence on a rigid surface such as a stress generated in the upper beam precast block during or after erection. Therefore, 1
It was assumed that the precast block having a length corresponding to the span of 50 m would have difficulty in rigidity and / or construction work. Therefore, the length of one precast block is set so that one span is basically divided into two.

[0006] However, even when the precast block is set to such a length, it is basically necessary to avoid the occurrence of partial stress concentration in the precast block due to the difference in height of the support portions.

Therefore, a main object of the present invention is to absorb a level difference of a support portion provided at a pile head of a foundation pile for supporting a precast block from below, and to reduce a rigidity or the like given to a pier upper beam portion during erection. To provide a precast pier structure with the same cross section as that of the cast-in-place RC method and a pier construction method using the same, by minimizing the influence and equalizing the supporting reaction force to the foundation pile after erection. It is in.

[0008]

In order to achieve the above-mentioned object, a precast pier structure according to the present invention comprises a foundation pile which is installed at a predetermined pitch on a water bottom along a quay length to be constructed, and a quay length in advance. It is manufactured as a beam part for the pier upper part of RC structure with divided RC structure, and is provided with a precast block having a sheath tube for being inserted into the pile head of the foundation pile at the time of erection and integrating with the foundation pile. . In this configuration,
A level adjustment bearing mechanism is installed at the bearing at the pile head of the foundation pile supporting the precast block. In this level adjusting support mechanism, a difference in height of the support portion due to a construction error or the like is absorbed when the precast block is erected, and the support reaction force of the foundation pile due to the weight of the precast block after the erection is equalized.

In the pier construction method using such a precast pier structure, a plurality of foundation piles are driven at a predetermined pitch along the length of the pier to be constructed, and are used as a beam for the pier upper construction of the RC structure. Precast blocks are prefabricated by dividing the wharf length, and when the precast blocks are erected on corresponding ones of the foundation piles that have been cast one by one, the number corresponding to the number of foundation piles provided on the precast blocks The sheath tube is inserted into the pile head of the foundation pile to position the precast block. At the time of positioning, the level adjustment support mechanism installed on the support part of the foundation pile absorbs the height difference of the support part of the foundation pile due to construction errors, and the support reaction force of the foundation pile due to the weight of the precast block after installation. Equalize.

The above procedure is repeated to connect another precast block to the positioned precast block in a span of 50 m.

Therefore, according to this wharf construction method, it is possible to separately manufacture a precast block to be a pier upper beam along with offshore work, thereby shortening the construction period. At that time, the height difference of the bearing part due to the construction error or the like is absorbed by the level adjustment bearing mechanism installed at the pile head of each foundation pile.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a precast pier structure according to an embodiment of the present invention and a pier construction method using the same will be described in detail with reference to the drawings.

FIG. 1 is a partial cross-sectional side view showing a form in which an existing caisson 1 that has been slid or inclined is restored by a pier construction method using a precast pier structure of the present invention on a pier damaged by a great earthquake or the like. The outline is that the beam part and the floor slab part of the pier superstructure are individually precast, and most of the beam part is integrated with the foundation pile (steel pipe pile) 20 after erection on site as a precast block 10 made on land. . The floor slab will be installed on the beam after the horizontal framing is performed on land as a PC hollow girder that can be separately manufactured at the factory.

FIGS. 2 to 6 show a production flow of the precast block 10 constituting one block of the pier superstructure. The extension of one span of the pier is 50 m, but in consideration of rigidity, workability, etc., a precast block 10 in which one span is basically divided into two is manufactured and erected at the site.

First, as shown in FIG. 2, a mold substrate 11 for one precast block 10 is prepared in a production yard on land. A plurality of sheath tubes 12 are arranged at appropriate intervals by the number corresponding to the number of piles.

Next, as shown in FIG. 3, a steel material 13 for erection of H-shaped steel is arranged in the length direction of the precast block so as to extend between the sheath pipes 12, and the reinforcing steel 14 is moved. Arrange the bars and arrange the suspension bars. After the arrangement, the formwork is assembled.

After the arrangement of the reinforcing bars and the formwork, as shown in FIG. 4, concrete is cast and the production of one precast block 10 is completed.

FIG. 5 is a plan view showing an example of the precast block 10, and FIG. 6 is a side sectional view taken along line AA of FIG. In this case, two parallel girder beams 1
5 shows a configuration in which a vehicle body is composed of 5 and three cross beams 16 orthogonal thereto, and the sheath tubes 12 are embedded in a number corresponding to the number of foundation piles. For one of the girder beams 15, the above-mentioned two erection steel members 13 from the entire length to the joint point.
Are inserted parallel to and embedded in the upper part of each sheath tube 12. Furthermore, in order to ensure thorough reinforcement during erection, etc., one of the longitudinal beams 15
Two erection steel materials 17 made of H-section steel are arranged so as to be exposed on the upper surface of the vehicle body.

On the other hand, in parallel with the production of the precast block 10 for the pier superstructure at the production yard, at the restoration site, as shown in FIG. Is laid on the seabed by a vibro hammer of a barge with a crane. FIG. 7 shows a mode in which the foundation pile 20 is driven at the set vertical and horizontal pitches,
FIG. 8 is a perspective view showing a pile head of the foundation pile 20. When the placing of the foundation pile 20 is completed, the precast block 10 is transported from the production yard to the construction site by the hoist ship shown in FIG. 9 and is laid on the driven foundation pile 20.

By the way, after the driving of the foundation pile 20, it is desirable that the error of the height level of the supporting portion installed thereon is ideally zero. However, FIG.
As shown in (1), in the pile head bearing of the foundation pile 20 that supports the precast block 10 from below, the height difference h of about ± 5 mm with respect to the reference level H stops being generated because of the on-site construction. Not get. A simple support beam with two support points at both ends is not a problem. As in this case, when one precast block 10 is supported by, for example, ten foundation piles 20 (see FIG. 5), the height difference h of each bearing portion locally causes excessive stress concentration on the precast block 10. Cause. This results in an uneven pile head reaction force, resulting in a residual axial force even for the foundation pile 20.

Therefore, in the present invention, as shown in FIGS. 11 and subsequent figures, a structure for absorbing the height difference h at the support portion of each foundation pile 20 is adopted.

FIG. 11 is a plan view of one foundation pile 20, and FIG. 12 is a sectional view of a support portion at the pile head of the foundation pile 20 along the line BB in FIG.

At the bearing portion of each foundation pile 20, a notch 21 is formed in the pile head, and the notch 21 is formed in the two parallel steel members 13 on the precast block 10 side shown in FIG. Can be inserted. Also,
The pile head of the foundation pile 20 is closed by an intermediate concrete 22 filled with concrete for shrinkage compensation.
The reference level H
A pair of left and right level adjustment support mechanisms 23 for adjusting the position are provided.

The level adjusting bearing mechanism 23 (a) absorbs the height difference h of the pile head bearing part in the foundation pile 20;
(B) After the precast block 10 is erected, each foundation pile 2
It is installed to achieve the two objectives of equalizing the support reaction force at zero. Therefore, a pair of opposed cushioning rubber members 24 which fulfill the purpose of (a) is provided at the upper part, and a pair of two pressure-sensitive cured rubber materials 25 which fulfill the purpose of (b) are provided at the lower part. Have. In addition, as a member for supporting the pressure-sensitive hardening rubber material 25 from below, it has a base 26 installed on the upper surface of the filling concrete 22.
Between the base 26 and the pressure-sensitive cured rubber material 25, a surface pressure adjusting plate 28 having the same plane size as the pressure-sensitive cured rubber material 25 is interposed. Further, a pressure-receiving partitioning plate 27 is interposed in the form of partitioning the pressure-sensitive hardening rubber member 25 and the cushioning rubber member 24 thereon, and the same pressure-receiving partitioning plate 27 is arranged on the cushioning rubber member 24 to form a laminated structure. ing. The level adjusting support member 23 of the laminated structure supports the erection steel material 13 from below.

Here, a steel plate is used for the base 26 installed on the upper surface of the filling concrete 22, and the reference level H
Is measured with the upper surface of the base 26. The base 26 whose level has been adjusted is installed when the concrete filling 22 is poured. After the concrete 22 is cast, the base 2
The level survey of No. 6 is performed, and a thin steel plate is installed as needed to match the reference level H.

The cushioning rubber material 24 of the upper layer sandwiched between the upper and lower pressure receiving partition plates 27 is elastically deformed in accordance with the weight of the precast block 10 at the time of erection. The pressure receiving partition plate 27 fluctuates following the elastic deformation of the cushion rubber material 24.
That is, the cushioning rubber material 24 is elastically deformed so that the foundation pile 2
The height difference h at the pile head bearing portion of zero, that is, the height difference due to a measurement error on the upper surface of the base 26 is absorbed. Due to its properties, the more flexible the rubber used, the greater the amount of distortion. That is, the lower the hardness, the more easily the height difference h is absorbed. Therefore, a generally used flexible rubber material having a hardness of 50 degrees is employed.

On the other hand, the base 2 for forming the lower layer
The pressure-sensitive cured rubber material 25 on 6 is a material having two very convenient characteristics, “plasticity before curing” and “elasticity after curing”. Its structure is a laminate of several layers of two types of unvulcanized rubber. The amount of plastic deformation before curing is 80% of the thickness.
It is. It is a rubber material exhibiting a function of equalizing uneven support reaction force in each foundation pile 20 by utilizing the characteristic of plastic deformation before hardening. In addition, this pressure-sensitive cured rubber material 25
The amount of plastic deformation depends on the applied load (surface pressure) per pressed area, and the larger the surface pressure, the larger the amount of deformation. Therefore, the surface pressure adjusting plate 28 having the same plane size as the pressure-sensitive cured rubber material 25 interposed on the base 26 can prevent the surface pressure from being equalized.

Therefore, when one precast block 10 is erected by a hoist ship as shown in FIG.
As shown in (1), first, the pile head of the foundation pile 20 corresponding to each sheath tube 12 on the precast block 10 side is inserted, and positioning by fine adjustment is performed. Sheath tube 1 on pile head of foundation pile 20
2, the precast block 10 is placed.
When the precast block 10 is placed on the pile heads of several foundation piles 20 via the two parallel steel materials 13 for erection,
Adjustment of the height difference h of the pile head bearing portion of each foundation pile 20 is schematically shown by a level adjustment bearing mechanism 23 on each foundation pile 20 in FIG.
As shown in FIG. 7 and FIG. 18, it is absorbed by elastic deformation.

As shown in FIG. 17, when one of the foundation piles 20 is at the reference level H, the height of the other foundation pile 20 is assumed to be higher by h. In this case, the other foundation pile 2
The level adjustment support mechanism 23 provided at 0 is elastically deformed to absorb the height difference h. For example, when the height difference h due to a construction error or the like on the upper surface of the base 26 is ± 5 mm, a difference occurs in the amount of distortion of the cushion rubber material 24 due to the weight of the precast block 10 after the construction, and the height difference h is absorbed. Thereafter, as shown in FIG. 18, a difference occurs in the amount of plastic deformation of the pressure-sensitive cured rubber material 25, and the amount of strain becomes uniform in each of the foundation piles 20 of the cushioning rubber material 24. The pressure-sensitive curable rubber material 25 is cured after being left for about one week in a state where plastic deformation has occurred, while maintaining the deformation amount.

As described above, the level adjustment support mechanism 23 adjusts the level of the precast block 10 based on the height difference of the pile head support portion of each foundation pile 20, and the support reaction force in each foundation pile 20 is made uniform. You. Then, FIG.
As shown in the figure, each sheath tube 1 on the precast block 10 side
The gap between the base 2 and the foundation pile 20 is filled with concrete 30 for shrinkage compensation, and the precast block 10 and the foundation pile 20 are integrally connected.

FIG. 15 shows a foundation pile 20 in the sheath tube 12 when the precast block 10 is viewed from this longitudinal direction.
2 shows a cross section of an integrated connection portion with the above. FIG. 16 is a cross-sectional view of an integrated connection part in a connection part when two adjacent left and right precast blocks 10A and 10B are viewed from their longitudinal direction. In the connection part of FIG. 16, the steel material 13 for erection is exposed to the outside at a predetermined length from the opposing surfaces of the precast blocks 10A and 10B facing each other. The opposite protruding end portions of the left and right precast blocks 10 and 10 in the steel materials 13 for erection are supported by one foundation pile 20 from below. At the top end of the foundation pile 20, a level adjustment support mechanism 23 corresponding to the facing protruding end of each of the erection steel materials 13 is arranged. After the erection, the reinforcing bars are joined by the enclosure joint 28, and concrete 30 for shrinkage compensation is cast at the connection portion to be integrated.

Although the present embodiment has been described assuming a construction method for emergency restoration of the damaged wharf, not only the construction method of a new wharf but also a construction method of a newly constructed wharf is basically used to shorten the construction period and save labor. Are of course applicable because they are common.

[0033]

As described above, the precast pier structure and the pier construction method using the same according to the present invention can separately manufacture a precast block to be a pier upper beam part along with offshore work. The level adjustment support mechanism installed at the pile head of each foundation pile achieves the shortening of the construction period, absorption of height differences due to construction errors at the pile head bearing of the foundation pile, and equalization of the support reaction force. . Also,
Since the offshore work is labor-saving as compared with the cast-in-place RC method, there is an effect of improving construction safety.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a damaged pier and a precast pier structure according to an embodiment of the present invention for restoring the pier.

FIG. 2 is a perspective view showing a step of manufacturing a precast block having an RC structure according to the present embodiment in a manufacturing yard.

FIG. 3 is a perspective view showing a step of manufacturing a precast block having an RC structure according to the present embodiment in a manufacturing yard.

FIG. 4 is a perspective view showing a step of manufacturing a precast block having an RC structure according to the present embodiment in a manufacturing yard.

FIG. 5 is a plan view showing a precast block of the present embodiment after fabrication.

FIG. 6 is a side sectional view taken along line AA of FIG. 5;

FIG. 7 is a perspective view showing an aspect during the placement of the foundation pile.

FIG. 8 is a perspective view showing a pile head of a foundation pile.

FIG. 9 is a perspective view showing an aspect in which a precast block is erected on a foundation pile.

FIG. 10 is a perspective view showing a height difference generated in a pile head bearing of a foundation pile after driving.

FIG. 11 is a plan view showing a level adjustment support mechanism of the present embodiment installed on a pile head support portion of each foundation pile.

FIG. 12 is a front sectional view taken along line BB of FIG. 11;

FIG. 13 is a side cross-sectional view showing the connection between a foundation pile and a precast block installed and positioned between the piles.

FIG. 14 is a front sectional view showing a state in which a gap between a sheath pipe on a precast block side and a pile head on a foundation pile side is filled with shrinkage compensating concrete and integrally combined.

FIG. 15 is a front sectional view showing the connection of the sheath pipe of the precast block with the pile head of the foundation pile.

FIG. 16 is a front cross-sectional view showing connection of a portion connecting adjacent precast blocks to a pile head of a foundation pile.

FIG. 17 is a sectional view schematically showing a level adjustment support mechanism at a height difference h generated in a pile head support portion of each foundation pile.

FIG. 18 is a cross-sectional view schematically showing a form in which a height difference h generated in a pile head bearing portion of each foundation pile is absorbed by a level adjustment bearing mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Caisson of quay quay 10 Precast block 12 Sheath tube 13 Steel material for construction 17 Steel material for construction 20 Foundation pile 21 Notch recess 22 Filling concrete 23 Level adjustment support mechanism 24 Buffer rubber material 25 Pressure sensitive rubber material 26 Base 27 Pressure receiving partition plate 28 Surface pressure adjusting plate 30 Concrete for shrinkage compensation

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Kanai 2-4-6 Bingo-cho, Chuo-ku, Osaka City, Osaka Prefecture Saeki Construction Industry Co., Ltd.

Claims (3)

[Claims] 1. A foundation pile which is laid at a predetermined pitch along the length of a quay along a pier length to be constructed, and a beam for a pier upper part of an RC structure having a quay length previously divided into pier lengths. A precast block that has a sheath tube to be inserted into the pile head of the pile and integrated with it, and a precast block that is installed at the bearing at the pile head of the foundation pile that supports the precast block, and the height difference of the bearing due to construction errors etc. And a level adjustment support mechanism for absorbing the weight of the precast block after the erection and equalizing the supporting reaction force of the foundation pile. 2. A level adjustment support mechanism, wherein a flat base provided on a support surface of the support portion and a top surface of the base are provided to adjust the installation height of the support portion to a reference level. A pressure-sensitive cured rubber material that avoids uniform surface pressure, plastically deforms according to the weight received from the precast block, and hardens while retaining the amount of plastic deformation to equalize the supporting reaction force of the foundation pile A cushioning rubber material that is arranged above this pressure-sensitive cured rubber material and absorbs the height difference of the upper surface of the base by elastically deforming according to the weight received from the precast block, and a pressure-sensitive cured rubber material and placed on top 2. The precast pier according to claim 1, further comprising: a pressure receiving partition plate comprising a plurality of upper and lower pressure plates which are interposed between the shock absorbing rubber material and the elastic deformation of the shock absorbing rubber material. Elephants. 3. A plurality of foundation piles are cast at predetermined pitches along the length of the pier on the pier to be constructed, and a precast block is preliminarily manufactured by dividing the pier length as a beam for an upper part of a pier having an RC structure. Then, when laying the precast blocks on corresponding ones of the foundation piles that have been cast in block by block, insert the sheath pipes of the number corresponding to the foundation piles provided in the precast blocks into the pile heads of the foundation piles. When positioning the precast block, the level adjustment support mechanism installed on the support on the foundation pile during positioning absorbs the height difference of the support on the foundation pile due to construction errors, etc. A wharf construction method using a precast pier structure, characterized by equalizing the supporting reaction force of a foundation pile by weight.