JPS5827384B2 - Construction method of underground tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The disclosed technology belongs to the technical field of constructing an underground tank such as a membrane L'MG tank by first constructing a roof and then constructing the tank under the roof with high efficiency.

Therefore, this invention relates to a method in which a roof such as a dome roof is constructed in advance after construction of a groundwater ice wall on the ground, and then concrete side walls and bottom slab are constructed after ground excavation and concrete work. In particular, after constructing a groundwater cut-off wall, a temporary support is established on the ground, a roof is first constructed and assembled on the support, and excavation is carried out under the roof after the construction of the roof starts or after completion. We carry out civil engineering works such as
Reinforcement is placed in the excavated hole, concrete is placed, etc. to form a concrete side wall and a bottom slab, and the roof is placed on the concrete side wall from a temporary support before and after forming the bottom slab, or before and after construction of the tank body. This invention relates to a method of constructing an underground tank in which the tank is completed by mounting and assembling the tank in turn.

As is well known, oil tanks, LNG storage tanks, etc. have recently been constructed from the viewpoint of expanding energy demand and increasing stockpiles, and their capacities are gradually increasing.

In view of pollution, disaster prevention, landscape, etc., many underground nuclide tanks are now being designed and constructed.

In general, when constructing an underground tank, whether it is a strength plate type or a pumped type, the underground tank is constructed by excavating the inside of the cutoff wall using an open cut after constructing the groundwater ice wall, and then reinforcing and concrete pouring. After constructing the facilities, the concrete frame was constructed, and then the dome roof, main body, etc. were constructed.

However, in the conventional construction method mentioned above, the roof construction is a post-process work, so the civil engineering work and some of the tank body work up to that point were done in an open type, and therefore the tank was exposed to the wind and rain. Various works were carried out at the base, which had the disadvantage of extremely low work efficiency and was also dangerous.

Furthermore, as the tank becomes larger, it is often difficult to carry in and out of the tank due to the lack of scaffolding at the top when carrying in equipment for excavation and concrete pouring of the tank body.

The purpose of this invention is to solve the problems of underground tank construction based on the above-mentioned conventional technology, and to construct a groundwater ice wall on the ground where the tank hole is constructed under the roof of the previous construction. To provide an excellent underground tank construction method that benefits the field of tank use in the storage industry by allowing excavation to be carried out without being affected by wind and rain, and by allowing civil engineering and construction work for the tank to be carried out smoothly and according to the construction plan. It is something.

In order to solve the above-mentioned problems, the structure of the present invention in accordance with the above-mentioned purpose is that, contrary to the conventional method, after the construction of a continuous underground water-stopping wall, a temporary support that has been established on the ground is constructed. The roof will be constructed in advance by installing the permanent roof, or the permanent roof and a temporary roof around it, and excavating the ground, placing reinforcement, placing concrete, etc. under the roof, and in the meantime, the equipment operator and soil removal The opening of the temporary support and the roof are used as scaffolding to function as a foothold, shielding from wind and rain and blocking groundwater from the side wall of the ground, allowing construction to proceed with high efficiency. The gist of this invention is to take technical measures that enable the tank to be completed by forming the main body and replacing the main roof on the side walls.

Next, an embodiment of a membrane type underground tank according to the present invention will be described below with reference to the drawings.

As shown in Figure 1, the ground 1 of the planned construction site is
As shown in the figure, a continuous underground wall C is constructed as a water stop wall to stop underground water, and foundations 2, 2, etc. are installed as appropriate along the circumference of a circle that is larger than the design tank outer diameter by a set diameter. Basics 2, 2
Establish a pillar 3.3 as a support on top of...
In this state, as shown in FIG. 3, the dome roof 4 is constructed during the preliminary construction using the pillars 3, 3, . . . as scaffolding.

Thus, the roof 4 is combined with the main roof 4' which is placed on the tank when completed, and its outer edge temporary roof 4", and the temporary roof 4" is removed from the main roof 4' in a subsequent process. It is possible to construct it.

Therefore, when the roof 4 is mounted on the pillars 3, 3, and constructed, gap openings 5, 5, and so on are formed between the pillars 3 and 3, as shown in the figure. It is used as the entrance for carrying in and out of equipment and the opening for discharging soil in the next process.

When the roof 4 is covered in this way, the opening 5
, 5..., and excavate a tank hole 6 of a set diameter in the ground 1 under the roof 4 concentrically with the roof 4, blocking groundwater from the side wall of the ground 1. The excavated earth and sand can be excavated using a winch or
The soil is removed from the openings 5, 5, .

Covered by the roof 4, the construction will not be affected by wind and rain.

At the same time as the tank hole 6 is excavated, reinforcing bars 10 are placed as shown in FIG. 5, and the formwork 11 is suspended and concrete is poured to form the side wall 12.

In addition, in the process of forming the side wall 12, depending on the excavation and construction conditions, either reverse winding construction or forward winding construction can be adopted as appropriate for concrete pouring.

In this way, the side wall 12 is formed in a predetermined manner and the equipment is carried out. Before and after the bottom plate 13 is formed, the support side plate 14 is placed on top of the upper end of the side wall 12 as shown in FIG. 6 based on the construction design. The formation of the tank frame A is completed by fixing it to the outer end of the main roof 4' of the roof 4 from below, removing the temporary roof 4'', and removing it together with the pillars 3, 3, etc. as appropriate. .

In the above-described process, when the temporary support 3 of the roof 4' is transferred to the tank side wall 12, the support side plate 14 may be omitted and transferred to the upper end of the installation side wall 12.

Further, in the above process, the temporary support may be made higher to position the roof during construction to be advantageous for carrying in equipment and construction work, and upon completion, the roof may be lowered by jacking or the like.

When the construction of the concrete frame A is completed in this way, as shown in FIG. Tank body B
construction work will be completed.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments, and various embodiments can be adopted.

Furthermore, it is also possible to remove the temporary roof 4'' after construction of the tank body.

It goes without saying that the target underground tank is not limited to an LNG membrane tank, but can also be applied to a general underground tank with a roof.

According to the invention described above, in the method of constructing an underground tank, first, a groundwater fire and ice wall is constructed on the ground, then a temporary support is established on the ground surface, and the temporary support is By constructing the roof in advance, there is an excellent effect that construction of the roof is extremely easy and can be done safely and efficiently.Moreover, since the roof can be constructed quickly, the construction period for tank construction can be reduced. There is also the advantage of being shortened 6. Also, since the tank hole is excavated in the ground below after the roof is installed on the temporary support, the civil engineering work, subsequent reinforcement arrangement, and concrete pouring will be affected by wind and rain. Do it without receiving
There are no obstacles caused by wind and rain, and from this point of view, the construction of the tank body can be done more efficiently and smoothly, and has the excellent effect of being able to be carried out according to the construction plan.

Furthermore, since civil engineering and construction work for the tank can be carried out under the roof, the framework of the roof can be used to easily hang equipment, assemble, set, and reset building material jigs, and it is easy to use large cranes. etc. are no longer necessary, which also has the effect of making work easier.

Therefore, the pre-constructed roof can be simply transferred to the top of the side wall, and it can be replaced without having to jack it up or side slide, which is an excellent effect without having to correct the accuracy. .

In addition, by constructing a groundwater cut-off wall in advance on the ground, groundwater from the side walls of the ground is blocked without entering the tank hole, which has the advantage of allowing smooth ground excavation for the tank hole. be.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 to 7 are explanatory drawings of the construction process of one embodiment. C...Groundwater cutoff wall, 4...Roof, 1
2... Concrete wall, 13... Bottom plate, 1... Ground, 3... Temporary support, B.
...tank body.

Claims (1)

[Claims] 1. In the underground tank construction method, which consists of civil engineering work and tank body construction, after constructing the groundwater ice wall, a temporary support is established on the set ground, and a dome roof larger than the specified size is pre-constructed on the temporary support. After the preliminary roof construction begins, civil engineering work and tank body work are carried out under the roof, and before and after the tank body work, the dome roof is transferred from the temporary support to the side plate and placed and assembled. A method of constructing an underground tank characterized by attaching the tank to the tank.