Safe, low-cost removal of underground steel Technical Department of Company P, a General Contractor
Extract buried steel safely, in a short term and at low-cost
Friction-reducing gel works in high-salt water
Company P is involved in many large and medium-sized public works projects throughout Japan. With the increase in redevelopment projects in front of terminal stations, it became necessary to extract steel materials buried underground as temporary earth retaining core materials. The technical department was overwhelmed with the need to develop a low-cost construction method that ensured safety for the adjacent ground.
* This is a hypothetical example posted as a reference for those with similar challenges
Challenges
We couldn't find a material that could reduce friction and make it easier to pull out the steel safely.
Mr. M, from the technical department in charge, looks back on the situation at the time as follows:
"Steel materials buried underground are extremely difficult to pull out due to the adhesion of the soil and mortar, as well as the setting of mortar in the base protection section. If they are pulled out forcefully, the soil will adhere to the steel material and it will be pulled out, which raises concerns about land subsidence. In addition, large heavy machinery is required to pull out this steel material, which is costly. Furthermore, if the pulling out process takes a long time, it could put pressure on the construction period and increase the total construction costs."
Mr. M and his team held daily discussions to develop a construction method. As a result, they came up with the idea of coating the surface of the steel with a material that would reduce friction between the steel and the ground or mortar.
Mr. M and his team conducted repeated experiments applying commercially available Inks & Coatings, but they were unable to achieve the desired results, and they began to feel a sense of giving up.
Key Challenges
There was a need to develop a method for extracting steel materials buried underground at low cost while ensuring safety for the surrounding ground.
The idea of applying a material that would reduce friction between the steel and the ground or mortar was proposed, but no effective material could be found.