Introduction of sewerage office construction

This method is often used for relatively large and long tunnel construction.
The tunnel is excavated while digging a steel excavator called a shield machine into the ground, and concrete and steel blocks called segments are assembled behind them to create tunnel walls. If this is the case, the surface will be uneven, so the inside may be rounded with concrete. A shaft is required to carry in shield machines and carry out earth and sand.

Excavation is made by a digging machine dug from the starting shaft, a propulsion pipe is connected behind the digging machine, and the propulsion pipe is pushed into the ground with a jack to build a pipeline.
A shaft is required to carry in digging machines and carry out earth and sand.

Construction of rainwater regulating ponds will be carried out to temporarily store rainwater and reduce flood damage​.
After excavating earth and sand, installing a concrete box-shaped structure (precast block), backfilling is performed.

A large-scale concrete structure will be built to build a facility for treating sewage.
Many types of work are often required, such as earth retaining work, excavation work, reinforcing work, formwork work, and concrete work, and the construction period is long.
Even after the structure is completed, equipment work to install machines for treating sewage and construction work to build buildings on the ground (management buildings, etc.) will be performed.

Reference photo

Squeezing (The steel pipe, which forms the basis of the structure, is inserted.)	Earth retaining work (Yaita work) (Long iron plates are embedded in the ground continuously.)
Earth retaining work (It looks like a wall after hitting the sheet pile.)	Excavation work
Reinforcement	Concrete

In a closed sewage treatment facility, hydrogen sulfide is generated, and concrete in the facility is gradually corroded.
In order to prevent corrosion, the concrete surface is coated with acid-resistant materials.
In existing facilities where corrosion has already progressed, the corroded concrete is cut off, repaired with mortar, and then coated with anticorrosion materials.

Reference photo

Dredging	Lower cleaning	Removal of degraded parts
Pre-section repair primer application	Anticorrosion coating (section repair)	Anti-corrosion coating (primer application before base adjustment)
Anticorrosion coating (ground adjustment)	Anti-corrosion coating (overpainting)	Anti-corrosion coating (top)

We make new pipe in old sewer pipe and plan update of pipe and earthquake resistance.
It may be carried out at night when the amount of sewage is low.