JP2506050B2 - Construction method of asphalt mastic layer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method for constructing an impermeable layer by asphalt mastic to prevent water from flowing from a foundation portion to a portion partitioned by a caisson or the like. The present invention relates to a construction method in which a partition member made of asphalt is arranged on the surface of an internal foundation rubble provided with, and asphalt mastic is poured onto the foundation rubble to construct an impermeable layer.

[0002]

2. Description of the Related Art When constructing a breakwater or a harbor facility, a method is used in which a foundation rubble is formed on the seabed and the upper surface of the foundation rubble is leveled and then caisson is constructed. There is. Further, the caisson built on the foundation rubble, in order to increase the frictional force between the upper surface of the foundation rubble, is fixed in the state of laying an asphalt mat,
Due to the weight of the caisson and the increase in frictional force due to the asphalt mat, a means for preventing the caisson from moving due to wave pressure is used. In offshore structures such as breakwaters described above, whether the foundation rubble that supports the lower part of the structure such as caisson is water-permeable or water-impermeable is important for the stability of the structure. It will have an impact.

For example, in the example disclosed in Japanese Patent Laid-Open No. 5-79025, when an asphalt mat is provided in a predetermined width with respect to the lower part of the caisson and the inland ocean section of the foundation rubble, the asphalt mat is permeable to water. It proposes to eliminate the effect of not having. Further, in the example disclosed in Japanese Patent Laid-Open No. 62-178612, etc., when the surface of the rubble of the foundation supporting the breakwater body of the breakwater is covered with an asphalt mat, a member having water permeability is arranged between the asphalt mats. Thus, the water-permeable member constitutes means for allowing only water to pass through without passing through earth and sand. And, as mentioned above, even when the asphalt mat is constructed on the surface of the foundation rubble such as a breakwater, the foundation rubble part supporting the structure such as caisson enables the circulation of water to the inside and outside of the breakwater. It is possible to prevent problems such as scour due to the influence of.

[0004]

However, when a partition is provided on the sea surface by the caisson or the like and the inner water portion of the partition is to be filled, if the material used for the landfill contains harmful substances, it is used for the landfill. From the material
It is necessary to prevent harmful substances from leaking out. Then, it is necessary to construct a water impermeable layer on the surface of the foundation rubble, etc. after taking measures so that the scour of the caisson support structure will not affect the demands of the site. Therefore, as mentioned above, an asphalt mat is constructed on the surface of the foundation rubble to support structures such as caisson, preventing seawater from entering the inside of the embankment from the open sea, and leaking water from the inside. Work is done to prevent this.

[0005] However, the construction of an asphalt mat on the surface of the foundation rubble to construct an impermeable layer means that the price of the asphalt mat is high, and that the surface of the foundation rubble is uniform in order to construct the asphalt mat. However, there is a problem that the construction cost of the offshore structure becomes relatively high because it is necessary to equalize it. In addition, when laying the asphalt mat on the surface of the rubble, it is necessary to perform relatively troublesome work such as overlapping the ends of adjacent asphalt mats and injecting asphalt for bonding between the asphalt mats to be connected. There is. Therefore, as described above, instead of laying an asphalt mat on the surface of the foundation rubble, for example, it has been proposed to flow asphalt to a uniform thickness to build an impermeable layer of asphalt mastic. .

In order to apply the above-mentioned asphalt mastic to the surface of a rubble, etc., for example, Japanese Patent Publication No. 55-42.
As shown in Japanese Patent Publication No. 205, etc., asphalt can be applied to the sea bottom using a flexible pipe body. However, when an asphalt mastic is constructed at a deep sea bottom using a pipe as disclosed in Japanese Patent Publication No. 55-42205, the depth of water at the construction site is 20 to 30 m. There is a problem that the workability is not good. Further, when the asphalt is constructed using the pipe body, it is difficult for the diving worker to move the construction site while holding the pipe body, and it is difficult to improve work efficiency.

Therefore, in order to solve the above-mentioned problems, an underwater construction method of asphalt using a bucket has been proposed as shown in Japanese Patent Laid-Open No. 5-79039. In the conventional example, the asphalt is stored in a bucket and lowered to the seabed by a crane or the like,
When the bucket reaches near the bottom of the sea, open the bottom plate and let the asphalt flow down so that it can be laid on the seabed with a uniform thickness due to the fluidity of the asphalt. Further, in the method of constructing asphalt using a bucket, a large amount of asphalt mastic can be constructed at one time, and the work efficiency in constructing an asphalt mastic layer on the seabed can be improved. However, when constructing an asphalt mastic layer using a bucket, there is a problem that it is difficult to apply it with a uniform thickness. It is desired to develop an auxiliary means for the uniform construction of the layers.

[0008]

An object of the present invention is to solve the above-mentioned problems of conventional underwater construction of asphalt, in which partitioning members made of asphalt are arranged in advance in the area where the asphalt mastic layer is to be constructed to divide the construction position into sections. It is an object of the present invention to provide a method of constructing an asphalt mastic layer that enables the thickness of the asphalt mastic layer to be specified.

[0009]

According to the present invention, a caisson is constructed through an asphalt mat on a foundation rubble provided on the seabed, and an impermeable layer is provided on the surface of the foundation rubble following the caisson. The present invention relates to a method of constructing an asphalt mastic layer when partitioning an inner surface partitioned by a caisson from the open ocean. In the present invention, formwork members made of asphalt material are arranged at a predetermined interval on the surface of the foundation rubble, and the formwork members are used to partition the place where asphalt is to be constructed, and the formwork members are used asphalt mastic. Corresponding to the construction thickness of, the asphalt mastic is flowed to the foundation rubble, a layer of a predetermined thickness is formed on the surface of the crushed stone of the foundation rubble, and a part of the asphalt mastic enters between the crushed stones. It is possible to use a means for causing the above to solidify together. Further, in the present invention, the formwork member is configured by sandwiching a reinforcing rebar and a fiber material between two upper and lower layers of asphalt, and a hanging member for connecting the reinforcing rebar to the formwork member. Is arranged at a predetermined interval in the length direction, the formwork member is installed in an asphalt mastic construction section of the foundation rubble surface, and it is possible to use a method of constructing asphalt mastic for the section partitioned by the formwork member. it can.

[0010]

In the present invention, the members made of asphalt are arranged at a predetermined interval with respect to the section for constructing the asphalt mastic layer, and the asphalt mastic is poured into the section partitioned by the formwork members by using a bucket. The construction thickness of the asphalt mastic layer can be easily controlled. In addition, when constructing an asphalt mastic layer on a relatively deep sea floor, the work area of the diving worker can be specified, so that the worker does not need to make extra movements and the asphalt mastic layer construction work can be performed. The efficiency can be improved. further,
When waterproofing the caisson foundation rubble in a large area, partitioning by formwork members, especially on the slope of the foundation rubble, will prevent asphalt from flowing into extra areas. Then, since the constructed asphalt mastic layer and the formwork member are solidified integrally, it is possible to maintain the water stopping performance in the inside and outside sea areas partitioned by the caisson, and to exert the waterproofing performance on the surface of the rubble basin satisfactorily.

[0011]

EXAMPLES The method of applying the asphalt mastic layer of the present invention will be described with reference to the examples shown in the drawings. The example shown in FIG. 1 shows a case where a landfill partition is constructed by caisson. A foundation rubble 6 is constructed on the seabed 5 and the asphalt mat 4 is laid on the bottom of the foundation. Building caisson 1 in the state. The caisson 1
Uses a construction method in which an iron caisson is created on land and transported to the installation site by sea, and then buried. Between the adjacent caisson 1, rubber inclusions 2 and 2a are used as joints. Place asphalt mastic 3 in between
Is used to show the water stopping property. The caisson may be made of concrete, and the asphalt mat 4 arranged on the lower surface of the caisson increases the friction of the caisson with respect to the rubble 6 for ensuring stability. I am able to do it.

On the inner water surface side partitioned by the caisson 1, a waterproof layer is constructed by providing an asphalt mastic layer 20 on the surface portion of the foundation rubble 6, and the waterproof layer is agitated by the force of the waves of the open sea. In order to prevent this, the crushed stone layer 8 is provided. The layer of the asphalt mastic 20 is constructed using a means for laying asphalt using a bucket, as will be described later, and has a thickness of about 15 cm and is constructed in the range from the lower part of the caisson to the seabed ground. , A coated crushed stone layer 8 for pressing the entire upper surface of the asphalt mastic layer 20. And
Affected by waves passing through the layers of foundation rubble 6, or
Due to the difference between the height HWL of the water surface at high tide in the open ocean and the height LWL of the water surface at low tide, and the fact that the water level inside the breakwater is constant, the asphalt mastic layer is lifted by water pressure. Be able to prevent being caught. As described above, in the case of constructing the asphalt mastic layer 20 on the surface of the foundation rubble 6, in order to improve the workability of the asphalt mastic, it is preferable to use a construction method of placing asphalt using a bucket. it can. Further, as the asphalt mastic, a mixture of asphalt with sand or gravel in a predetermined ratio is used, the asphalt mastic is heated to improve the fluidity and flow to the seabed, and the asphalt mastic layer is constructed. Allow the asphalt to flow more evenly in the area.

In order to apply the asphalt to the seabed using a bucket, for example, a bucket device as disclosed in Japanese Patent Laid-Open No. 5-79039 can be used. The improved asphalt is stored in a bucket, suspended at the construction position by a crane installed on the berth, the bottom lid of the bucket is opened at the construction position, and the asphalt mastic is constructed on the rubble. As described above, when the asphalt mastic is constructed, in order to set the construction position of the layer of the asphalt mastic with respect to the surface of the rubble and to define the construction thickness, in the present invention, FIGS.
A mold member 10 as shown in is used. The formwork member 10 shown in the figure has a thickness H formed to be higher than the construction thickness of the asphalt mastic layer, and a width W of 30 to 50 c.
m and length L shall be 3 to 5 m, and suspended by a crane so that they can be positioned on the rubble of the foundation in the construction area on the seabed.

The frame member 10 is made of the same material as the asphalt to be applied as the asphalt mastic layer. The upper and lower asphalt layers 1
Vertical and horizontal reinforcing bars 12, 15 and glass cloth 1 between 1, 14
The three layers are arranged and connected together by asphalt. The glass cloth 13 performs a process of impregnating asphalt between the fibers of a mesh-like woven fabric formed of glass fibers or the like, so that the connectivity with the upper and lower asphalt can be excellently exhibited. . Further, in the formwork member, an end portion of a wire provided as a horizontal reinforcing bar is bent upward to form a suspending reinforcing bar 16, and the suspending reinforcing bar 16 ... The handleability of the frame member 10 can be improved. The form member 10 may be of any size in order to improve the handleability of the form member and the workability of asphalt. When a member made of asphalt is used as the mold member 10, when the asphalt mastic is constructed in water, the work section can be set in a good condition by the mold member, and the asphalt mastic can be set. It is possible to exhibit good waterproofness without forming a gap with the asphalt constructed as the layer.

When constructing an asphalt mastic layer using the formwork members constructed as described above, as shown in FIGS. 5 and 6, the formwork members are arranged on the surface of the foundation rubble and the asphalt is used. The mastic construction area can be divided. The example shown in FIG. 5 shows a case in which an asphalt mastic layer is applied so as to cover the entire surface of the foundation rubble 6 inside the seabed defined by the caisson 1 of FIG. The part where the asphalt mastic is constructed should be divided into an upper horizontal part 25 continuing from the top where the caisson 1 is installed, a lower horizontal part 27 as a surface part of the seabed ground 5, and a slope part 26 of the foundation rubble 6. You can Then, in the embodiment of the present invention, as shown in FIG. 6, the form members 10, 10a, ...
Are arranged in rows, and asphalt mastics are sequentially installed in the area defined by the form members from the above direction. Therefore, by flowing the asphalt mastic to the slope portion of the foundation rubble by using a bucket, the asphalt flows on the construction surface and a layer of the asphalt mastic can be constructed with a predetermined thickness.

As described above, when a layer of asphalt mastic is applied to the surface of the foundation rubble, as shown in FIG. 7, the asphalt mastic flowed to the surface of the foundation rubble causes the fluidity of the asphalt mastic. Part of the material enters between the crushed stones of the basic rubble and fills a gap between the crushed stones to form a solidified portion 21. Then, a layer 20 of asphalt mastic for covering the surface of the crushed stone with a predetermined thickness
And the portion 21 connecting the crushed stones are integrated with each other to cover the surface of the foundation rubble, so that it is possible to favorably exhibit the water stopping property with respect to the surface of the foundation rubble. Further, as shown in FIG. 1, the coated crushed stone layer 8 is applied on the asphalt mastic layer 20, so that the stability of the asphalt mastic layer 20 can be maintained well. In the construction example of the asphalt mastic of the present invention shown in FIG. 7, if the thickness of the asphalt mastic layer is formed to be lower than the height of the formwork member 10, the depth of the sea floor becomes deep. The workability of the asphalt can be favorably maintained, but the relationship between the height of the mold member and the thickness of the asphalt mastic layer can be arbitrarily set. Further, the mold member used in the present invention can be configured to have a relatively large specific gravity so that the asphalt mastic does not easily move under the pressure when flowing from the bucket. When arranging the stones on the surface of the foundation rubble, it is possible to perform a treatment for preventing the form member from moving by using the stone of the foundation rubble.

In the method for constructing the asphalt mastic layer of the present invention, the construction for maintaining the water stopping property is performed as described above, so that, for example, the water depth for constructing the caisson is 20 m or more, and the difference between the low tide and the high tide. Even if it is 2 m, it is possible to maintain good waterproofness against the inner part of the breakwater. And, even if the thickness of the asphalt mastic covering the surface of the foundation rubble is about 15 cm, by forming the coated crushed stone layer 8 having a thickness of 1 to 2 m on the layer 20 of the asphalt mastic, It prevents the asphalt mastic from being affected by waves and changes in water pressure and impairing water stopping performance. Therefore, even before the dumping of the earth and sand for land reclamation into the internal area partitioned by the breakwater, the water flow in the internal and external water areas can be prevented. In the embodiment shown in FIG. 6 of the present invention, only in the slope direction of the foundation rubble,
Although the method of arranging the form members in parallel is used, it is also possible to set a section for forming asphalt mastic by arranging the form members in a direction perpendicular to each other between the form members perpendicular to the caisson.

[0018]

EFFECTS OF THE INVENTION The water stop layer provided on the foundation rubble of the construction part of the breakwater according to the present invention is constructed as described above, and a member made of asphalt is set to a predetermined area for constructing an asphalt mastic layer. It is possible to easily control the construction thickness of the asphalt mastic layer by arranging the asphalt mastic at intervals and pouring the asphalt mastic into the section partitioned by the formwork member using a bucket. In addition, when constructing an asphalt mastic layer on a relatively deep sea floor, the work area of the diving worker can be specified, so that the worker does not need to make extra movements and the asphalt mastic layer construction work can be performed. The efficiency can be improved. Further, when waterproofing the foundation rubble of the caisson in a wide area, the asphalt does not flow to an extra area by providing the partition by the form member especially on the slope of the foundation rubble. Then, since the constructed asphalt mastic layer and the formwork member are solidified integrally, it is possible to maintain the water stopping performance in the inside and outside sea areas partitioned by the caisson, and to exert the waterproofing performance on the surface of the rubble basin satisfactorily.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the structure of a breakwater to which the method for applying an asphalt mastic layer of the present invention can be applied.

FIG. 2 is a side view of a mold member used in the present invention.

FIG. 3 is a sectional view of a mold member.

FIG. 4 is a plan view of a mold member.

FIG. 5 is an explanatory diagram of a state in which the formwork member is applied to the foundation rubble.

FIG. 6 is a plan view showing a construction state of a mold member.

FIG. 7 is an explanatory view showing a state in which asphalt mastic is flown on the foundation rubble.

[Explanation of symbols]

1 caisson, 4 asphalt mat, 5
Submarine ground, 6 foundation rubble, 8 coated crushed stone layer,
10 formwork members, 12 vertical rebars, 13 glass cloth, 16 suspension rebars, 20 layers of asphalt mastic, 25 upper horizontal parts, 26 sloped parts,
27 Lower horizontal part.

Claims (2)

(57) [Claims] 1. A caisson is constructed on a rubble of a foundation provided on the seabed through an asphalt mat, and an impermeable layer is provided on the surface of the rubble of the foundation following the caisson, and an inner surface partitioned by the caisson is formed. When partitioning with the open sea, formwork members made of asphalt material are arranged at a predetermined interval on the surface of the foundation rubble, and the formwork members are used to partition the place where asphalt is to be constructed, and the formwork members are used asphalt mastic. Corresponding to the construction thickness of, the asphalt mastic is flowed to the foundation rubble, a layer of a predetermined thickness is formed on the surface of the crushed stone of the foundation rubble, and a part of the asphalt mastic enters between the crushed stones. A method of constructing an asphalt mastic layer characterized by allowing it to solidify together. 2. The formwork member is configured by sandwiching a reinforcing rebar and a fibrous material between two upper and lower layers of asphalt, and a hanging member connected to the reinforcing rebar is long with respect to the formwork member. Arranged at a predetermined interval in the vertical direction, the formwork member is installed in an asphalt mastic construction section of the foundation rubble surface, and asphalt mastic is constructed in the section partitioned by the formwork member. The construction method of the asphalt mastic layer according to 1.