Construction Method for Structure

The present invention relates to a construction method for a structure.

In order to form a foundation of a workpiece such as a building, for example, there is a case where a footing is constructed in a ground (refer to, for example, Patent Literature 1).

Patent Literature 1: JP 2003-193482 A

When it is necessary to allow a heavy object such as a transportation device that transports a heavy structure or a heavy machine to travel during construction of a workpiece, it is desirable to install an underground structure in a range that does not affect a travel route of the heavy object. However, there is a case where the underground structure is installed in the range in which the travel route of the heavy object is affected for convenience of site, design or the like.

In a case where construction of the underground structure is completed before traveling of the heavy object or construction of the underground structure is started after traveling of the heavy object, there are temporal and spatial restrictions.

When the construction of the underground structure is completed before traveling of the heavy object, if a part of the underground structure protrudes to the ground, traveling of the heavy object is hindered.

When the construction of the underground structure is started after traveling of the heavy object, construction work using a heavy structure carried in by traveling of the heavy object and/or a heavy machine is started, and thus there is a possibility that this construction work and the construction of the underground structure mutually affect.

An object of the present invention is to provide a construction method for a structure with little temporal or spatial restriction in a case where at least a part of the structure is arranged below a ground surface.

A first aspect of the present invention is a construction method of a structure provided with a lower structure part entirely arranged below a ground surface and an upper structure part at least a part of which is arranged below the ground surface on the lower structure part, the construction method including a step of constructing the lower structure part below the ground surface, a step of allowing a heavy object to travel on a travel route including a range that affects the lower structure part after the lower structure part is constructed, and a step of constructing the upper structure part on the lower structure part after the heavy object is allowed to travel.

In a second aspect of the present invention according to the first aspect, the travel route is temporarily provided after the lower structure part is constructed, and the travel route is removed before the upper structure part is constructed.

In a third aspect of the present invention according to the second aspect, the travel route is temporarily provided by backfilling the lower structure part.

In a fourth aspect of the present invention according to any one of the first to third aspects, a part of the upper structure part is constructed so as to protrude to a ground.

In a fifth aspect of the present invention according to any one of the first to fourth aspects, the structure is a foundation provided with a footing serving as the lower structure part and a pedestal serving as the upper structure part, and at the step of constructing the lower structure part, the footing is constructed so as to include a reinforcing bar joined to the pedestal.

In a sixth aspect of the present invention according to the fifth aspect, at the step of constructing the lower structure part, the footing is constructed so as to include at least a part of a mechanical joint, and at the step of constructing the upper structure part, the pedestal is constructed so as to include a reinforcing bar joined to the footing, and the reinforcing bar of the footing and the reinforcing bar of the pedestal are joined to each other using the mechanical joint.

In a seventh aspect of the present invention according to any one of the first to fourth aspects, the structure includes a cavity in the structure, at the step of constructing the lower structure part, construction is performed in such a manner that the cavity opens upward, and a temporary lid is further installed in the cavity, and at the step of constructing the upper structure part, the temporary lid is removed.

According to a first aspect, construction of an underground structure precedes in a range

in which traveling of a heavy object is not hindered, so that temporal or spatial restriction can be reduced.

According to a second aspect, traveling of the heavy object can be stabilized.

According to a third aspect, it is possible to suppress an influence of traveling of the heavy object on a lower structure part.

According to a fourth aspect, even in a case where a part of the underground structure is constructed so as to protrude to a ground, the heavy object can be allowed to travel without being spatially affected by a protruding portion.

According to a fifth aspect, a temporal or spatial restriction can be reduced in construction of a foundation including a footing and a pedestal.

According to a sixth aspect, the footing and the pedestal can be joined to each other by a more simple method.

According to a seventh aspect, it is possible to reduce temporal or spatial restriction in the structure with a cavity inside.

Hereinafter, the present invention will be described on the basis of preferred embodiments.

As a first embodiment,illustrate an example of a step of constructing a foundation. The foundationillustrated inis provided with a footingserving as a lower structure part and a pedestalserving as an upper structure part.

The footingand the pedestalin the first embodiment are an example of the lower structure part and the upper structure part of a structure, respectively. Also in a case of constructing an underground structure other than the foundation, treatment for the footingcan be applied to another lower structure part, or treatment for the pedestalcan be applied to another upper structure part.

An entire footingis arranged below a ground surface. At least a part of the pedestalis arranged below the ground surface on the footing. The pedestalmay include a portion protruding above a ground G.

On the pedestal, although not particularly illustrated, a workpiece is constructed after the foundationis completed. The workpiece is not particularly limited, and examples thereof include a building, a steel tower, a bridge, a storage tank, a pipeline or the like.

Prior to a step of constructing the footing, for example, level concrete L is formed at a bottom of a hole or a groove excavated from the ground G to a predetermined depth. The footingin the illustrated example is a reinforced concrete construction including concreteand a reinforcing barThe reinforcing barincluded in the footingis joined to the pedestal.

The reinforcing barof the footingand a reinforcing barof the pedestalare joined to each other by using a joint. As the joint, a welding joint, a gas pressure welding joint, a lap joint or the like is also used, but it is preferable to perform joining using a mechanical joint. This makes it possible to join the footingand the pedestalto each other by a simple method.

The mechanical jointis not particularly limited, but the mechanical jointincluding a steel pipe such as a coupler and a sleeve is preferable in order to enable transmission of a tensile force between the reinforcing barsandof both: examples of connection between the reinforcing barsandand the mechanical jointinclude a screw type, a bolt type, a mortar filling type, a grout fixing type, a friction welding type, a sleeve crimping type, a wedge fixing type, and a combination type in which two or more of them are used in combination.

By using the mechanical jointfor the reinforcing barsandof the footingand the pedestal, respectively, a construction schedule can be shortened. The mechanical jointdoes not require a high level of skill as compared with the welding joint or gas pressure welding joint, and has an advantage that a joint length of the reinforcing bar can be shortened as compared with the lap joint, and protection of the reinforcing bar in a joint length portion can be simplified.

As illustrated in, at a step of constructing the footing, it is preferable to construct the footingso as to include at least a part of the mechanical joint. This makes it easier to join the reinforcing barsandat a subsequent step.

In the illustrated example, the mechanical jointis arranged within the footing. Since the reinforcing barand the mechanical jointdo not protrude above the footing, they are less likely to interfere with traveling of a heavy object H. Since the reinforcing barof the footingis embedded in the concreterusting of the reinforcing barcan be suppressed.

Although not particularly illustrated, a position of the mechanical jointin a length direction of the reinforcing barsandmay be shifted for every reinforcing barsandIt is also possible to arrange the mechanical jointon the pedestalside with the reinforcing barof the footingprotruding above the footing. In this case, after joining the reinforcing barsandto each other via the mechanical joint, the mechanical jointis embedded in the concreteof the pedestal.

When the footingis completed, a protectionmay be applied to the mechanical joint. The protectionin the illustrated example includes a capfor preventing rust and dust inside the mechanical jointand a coverfor protecting the capA plastic material or the like is used for the capand wood or the like is used for the coverbut the material is not particularly limited.

Before constructing the pedestal, the heavy object H is allowed to travel on a travel route W including a range that affects the footing. At a step of allowing the heavy object H to travel, removal of an enclosure around the travel route W, entry permission for the heavy object H or the like can be performed as necessary so that the heavy object H can travel. A transportation device or the like that corresponds to the heavy object H may be operated by a person different from a person who performs construction work.

The travel route W is set within a range in which the traveling of the heavy object H dynamically affects the footing. Even if there is no margin space for setting the travel route W at a position not affecting the footing, the heavy object H can be allowed to travel. In a case where a plurality of footingis installed, the travel route W may be set so as to include a range that affects a part of the footings.

The position of the travel route W may be on the footing, may be a position vertically overlapping the footing, or may be slightly displaced in a horizontal direction from the footing. An amount of displacement in the horizontal direction may be, for example, 1 m or less, 2 m or less or the like depending on a situation. An influence of the heavy object H on the footingis preferably such that a load of the heavy object H might act on the footingbut does not adversely affect the same.

A temporary travel route W is preferably arranged on the footing. As a result, even in a case where the footingis not suitable for traveling of the heavy object H thereon, the heavy object H can be allowed to stably travel. For the temporary travel route W, one or two more materials such as a steel plate, a scaffold, a temporary bridge, a veneer plate, and a waterproof sheet may be used.

A part of the pedestalout of the foundationis constructed so as to protrude to the ground. Since the travel route W is installed before the pedestalis constructed, the heavy object H can be allowed to travel without the pedestalprotruding to the ground affecting the travel route W.

The travel route W can be temporarily provided by backfilling the footing. In a case where a height of the footingis lower than a surface of the surrounding ground G, a height of the travel route W may be leveled using a backfilling material such as earth and sand. As a result, a pressure by traveling of the heavy object H acts more uniformly on the travel route W, so that it is possible to suppress the influence on the footing.

The backfilling material is not particularly limited, but it is preferable that the travel route W can be easily removed before the pedestalis constructed, and examples thereof include sand, soil, gravel, clay, crushed stone, mineral dust or the like, for example. The earth and sand generated by excavating the ground G may be used as the backfilling material. In order to suppress sinking of the travel route W, it is preferable to appropriately perform compaction. A depth of backfilling is not particularly limited, and is, for example, about 50 cm to 3 m.

The heavy object H allowed to travel on the travel route W is not particularly limited, and examples thereof include a transportation device that transports a heavy structure, a heavy machine or the like. A weight of the heavy object His not particularly limited, but is, for example, 2 t or more with 1000 kg as 1 t, and may include 10 t or more, 100 t or more, 1000 t or more or the like.

In a case where the heavy object H is the transportation device that transports the heavy structure, a total weight of the transportation device including a weight of the heavy structure may reach the weight of the heavy object H. A case where the total weight reaches the weight of the heavy object H by loading a large amount of steel frames or the like may also be included in the heavy object H. On the travel route W, a machine or a person lighter than the heavy object H may pass.

The heavy structure is not particularly limited, but is a structure that serves as a part of various workpieces or is used for equipment or the like, and examples thereof include a large device a module or the like, for example. The transportation device is not particularly limited, and examples thereof include a truck, a trailer and the like.

The heavy machine is not particularly limited, and examples thereof include a construction machine, a work machine or the like, for example, which are machines used for constructing various workpieces. A use of the heavy machine is not particularly limited, and this is used for excavating, leveling, transporting, loading and unloading, lifting, paving, dismantling, crushing, cleaning, and snowplowing.

The above-described various workpieces are not limited to the foundationor the workpiece to be constructed thereon, and may be a workpiece to be constructed in another place. For example, in a case of constructing a plant, it is possible to allow the heavy object H used for any workpiece to travel on the travel route W in a planned plant site.

After the heavy object H is allowed to travel, the pedestalis constructed on the footing. In a case where the travel route W is temporarily provided, the travel route W is removed from above the footing. The pedestalin the illustrated example is a reinforced concrete construction including concreteand the reinforcing barThe reinforcing barincluded in the pedestalis joined to the footing.

After exposing at least an upper part of the footing, the mechanical jointis used to connect the reinforcing barof the footingto the reinforcing barof the pedestal. Concreteis placed around the reinforcing barand the pedestalis constructed.