JPS58138814A - Construction of underwater structure - Google Patents

Abstract

PURPOSE:To simply construct an underwater structure in a short time by a method in which outer concrete walls previously molded on the land are installed along steel pipe piles and then concrete is placed between the outer walls and the other form. CONSTITUTION:An outer concrete wall 3 previously cast on the land is supported under water through the brackets 12 and 12' of steel pipe piles 2, and then an inner form 4 to construct an inner wall is set concentrically with the outer wall 3. Then, filling concrete 5 is placed between the outer wall 3 and the inner form 4 through a tremie tube 14. In case where the height is short for the underwater foundation, the filling concrete 5 is further placed after additionally constructing and setting the concrete outer wall 3 and the inner form 4, and cement mortar is injected into both joints for joint treatment.

Description

Detailed Description of the Invention The present invention relates to a method for constructing underwater tanks, and in particular, by using a part of a structure previously constructed on land as a formwork and integrating it with concrete poured underwater. We propose a 77-method for constructing structures.

Conventionally, the construction method for underwater concrete structures involves attaching a pair of steel formworks via brackets to true pipe piles of 1w, placing filling concrete between the formworks, and constructing the facing formwork. They buried it to death, but removed it and built an underwater structure. However, in the case of the above-mentioned conventional construction method, it is mainly the H method in which panel steel formwork is installed in rows, so supporting and reinforcing the formwork is difficult and takes time, and especially in offshore work, wind It is weak and unstable against waves and waves. ■It is difficult to remove and collect the formwork after pouring the filling concrete.
There were drawbacks such as 11% unfavorable in case of 101% yield.

The purpose of this invention is to overcome the drawbacks of the above-mentioned construction method, and it is possible to do so under water.

When constructing a concrete structure, the W1 shell-shaped concrete outer wall that forms part of the structure wall is cast and formed in advance.
This Funkrete outer wall is installed at a predetermined position along the true pipe piles to which the temporary brackets are fixed, and then filling concrete is poured between the concrete outer wall and the pond formwork to form the cylindrical concrete wall. The feature of the structure is that it is an integral structure that includes a part of it. The details of the configuration will be explained below.

Figure 1 of the drawings is a general view of a pipe bridge or road bridge that requires the underwater structure according to the present invention, and Figures 2, 8, and 8 show detailed views of the underwater foundation thereof. The illustrated underwater structure is an example of a pillar base, and has a configuration in which an elongated cylindrical structure wall 1 is supported at a predetermined position by a plurality of steel pipe piles 2 driven into soil. To explain the underwater structure according to the present invention in the order of construction steps, the fiIi shell-shaped concrete outer wall 8 forming the outer peripheral wall and the formwork 4 forming the inner peripheral wall are prepared in advance, and then the filling concrete 5 is prepared. Constructed by pouring process.

As the formwork 4, one made of steel and one made of concrete are used, but in the case of the former it is necessary to remove it later as in the conventional method, whereas in the case of the latter it is necessary to remove it later as in the case of the concrete outer wall 8. It is integrated as part of the structure wall 1 when the filling concrete 5 is placed. One of the features of the construction method of the present invention is that the parts that make up the inner and outer walls of the structure are formed in advance on land, and this is used in place of conventional formwork, while at the same time forming part of the structure. The main point is that all five types of filling concrete are integrated as a part.

In addition, 6, 6', and 6' shown in the figure are all reinforcing bars to be buried, and 7 is a reinforcing reinforcing bar protruding from the steel pipe pile. The details of the reinforcement arrangement are shown in Fig. 4. 8 shown in FIG. 4 is an inner-outer wall 8,
4 and the filling concrete concrete 5 are reinforced reinforcing bars, which are fixed in a form protruding from support plates 9 buried in each wall toward the filling concrete placement space.

FIG. 5 shows each stage of the construction method of the present invention. First, the concrete outer wall 8 that constitutes the outer wall of the structure on land
Manufacture. At the same time, a steel pipe pile 2 is driven into the position for underwater installation, and the steel pipe pile 2 has a bracket 12 for supporting the above-mentioned concrete exterior 1 8 at a predetermined position underwater.
Fix 12'. 'Bracket 12.12'
Since the fixing position is underwater, for convenience of work, dummy bars 12a and 12'a are protruded from the bracket, and the dummy bars 12a and 12'a are brought above the water surface along the stakes, and the upper part located above the water surface is Fix by welding and decide the bracket position. The concrete outer wall 3 is attached to the W4 pipe pile 2 prepared in this way by a crane ship 10 and a barge 11 with a bracket 1.
2. Support in water via 12'. Thereafter, an inner formwork 4 made of concrete or steel for forming the inner wall is installed a concentrically with the outer wall 8. The details of the concrete exterior 3 and formwork 4 support patterns are shown in Figures 6 and 7.
As shown in the figure.

After completing the above steps, filling concrete 5 is placed between the outside concrete 1118 and the inner formwork 4 using the tremie pipe 14. When pouring, be careful not to spill out the filling concrete as shown in Figure 8.

An embankment 18 as shown in FIG. 9 is constructed in advance.

After that, if it is necessary to divide the construction into several blocks in order to obtain the required height for the underwater foundation, repeat the same process described above as shown in (d) and (e) in Figure 5. Filling concrete IJ-1 and 5 were cast in the darkness between the concrete outer wall 3 and inner formwork 4, joints were treated by pouring mortar into the solid joints, and the concrete was overlaid to the required height to complete the work. let

Example: The effectiveness of the present invention was confirmed in the construction of a piping bridge column pedestal foundation in the construction of a cross-pipeline for high beams to send C gas and N gas generated at the Hijima Steel Works to a factory on the opposite bank across the high beams. An example in which the method of the present invention was applied on a trial basis to achieve this will be explained.

Figure 10 (a).

(B) is a detailed view of the foundation, which has an oval column base measuring 7.8 m long, 4.3 m wide, and 9.4 m high. Of the 80cm thick column pedestal wall, a 15cm concrete outer wall was divided into two 4.5m high blocks that had been fabricated on land in advance. As a result of this implementation, the construction period was shortened by about 10 days compared to the conventional method, and the work went extremely smoothly.

As explained above, according to the present invention, since the concrete outer wall also serves as the formwork, there is no need to assemble or remove the formwork on the water, so the construction work is simple and the construction period can be shortened. It is also superior to conventional models in terms of aesthetics.

[Brief explanation of drawings]

Fig. 1 shows a general example of a column base foundation [E side view, Fig. 2 (a), (b), and Fig. 8 (a), (b) are all examples of construction according to the present invention. Fig. 4 (a) and (b) are partial sectional views of the structure wall, and Fig. 5 shows each stage of the construction method of the present invention. Fig. 6 (a) and (b) are cross-sectional views showing the pattern of the concrete outer wall and formwork support by brackets, Fig. 7 is a front view showing details of the brackets, Figs. 8 and 9 The figure is a sectional view of the embankment constructed under the structure, and Figure 1O (a) and (b) are both cutaway sectional views of the column base of the example. ■...Underwater structure wall 2...m pipe pile 8...Concrete outer wall 4...Formwork (for inner wall) 5...Applicable concrete 6.6', 7.8... Rebar 9...
Support plate IO... Crane ship 11... Barge 12.12'... Bracket 12 a
, 12'a... Bracket dummy par 18...
・Embankment 14... Tremie pipe patent applicant
Kawasaki Steel Co., Ltd. Figure 4 (In 1) 79- JP-A-58-138814 (6)

Claims (1)

[Claims] 1. When constructing a concrete structure underwater, a cylindrical concrete IJ-) outside 11 that forms part of the wall of the structure is prepared in advance.
i was cast and formed, and this concrete outer wall was installed in a predetermined position along the true pipe piles to which temporary brackets were fixed.
An underwater structure characterized in that filling concrete is then placed between the concrete outer wall and another formwork to form an integral structure including the cylindrical shell-shaped concrete outer wall in its part. Construction method H. a. The method according to claim 1, wherein the pond formwork is a cylindrical concrete wall or a steel frame.