Okumura-Marugo Enlarged-Base Pile Construction Method (OMR/B-2) Expanded with New Construction Method
Okumura Corporation and Marugo Kiso Kogyo Co., Ltd. have expanded their jointly developed enlarged-base pile construction method, "Okumura-Marugo Enlarged-Base Pile Construction Method (OMR/B-2)," by adding a construction method utilizing a full-rotation machine. They re-acquired technical certification (BL Certification - 060) from Better Living on January 6, 2026. This new method aims to reduce construction time and costs, and ensure ground stability in urban redevelopment projects where underground obstacles are present. The method integrates shaft excavation, underground obstacle removal, and enlarged-base excavation using a full-rotation machine and a specialized jig (patent pending).
📋 Article Processing Timeline
- 📰 Published: April 14, 2026 at 18:00
- 🔍 Collected: April 14, 2026 at 09:31
- 🤖 AI Analyzed: April 16, 2026 at 17:33 (56h 1m after Collected)
Okumura Corporation (Headquarters: Abeno-ku, Osaka, Representative Director and President: Takanori Okumura) and Marugo Kiso Kogyo Co., Ltd. (Headquarters: Chuo-ku, Osaka, Representative Director and President: Yoshihiro Tokuyama) have expanded the construction method for their jointly developed enlarged-base pile method. They have added a construction method using a full-rotation machine and renamed the method to "Okumura-Marugo Enlarged-Base Pile Construction Method (OMR/B-2)." They re-acquired technical certification (BL Certification - 060) from Better Living on January 6, 2026.
Background:
In urban redevelopment projects, the presence of underground obstacles can sometimes prevent the excavation of pile shafts using earth drill machines. Therefore, the conventional "Okumura-Marugo Pull-out Resistance Pile Construction Method (OMR/B-2)" required the removal of underground obstacles interfering with the pile using a full-rotation machine, followed by temporary backfilling with fluidized soil, before constructing enlarged-base piles with an earth drill machine. This involved many steps and presented challenges in terms of construction efficiency.
To address this, both companies added a method that performs shaft excavation, underground obstacle removal, and enlarged-base excavation consistently with a full-rotation machine, and confirmed its effectiveness through full-scale testing. With the expansion of the construction method, the method name was changed to "Okumura-Marugo Enlarged-Base Pile Construction Method (OMR/B-2)" (hereinafter, "this method"), and technical certification (BL Certification - 060) from Better Living was re-acquired.
Added Construction Method Using a Full-Rotation Machine:
After shaft excavation, the casing in the enlarged-base area is pulled out, and the upper casing is set on the full-rotation machine.
The full-rotation machine rotates the upper casing, and its rotational force is transmitted to the Kelly bar by a specialized jig (patent pending).
The OMR/B-2 excavator attached to the bottom end of the Kelly bar rotates and excavates the enlarged base.
Benefits:
When underground obstacles are present, enlarged-base piles can be constructed using a full-rotation machine and a crane, without using an earth drill machine, thereby reducing construction time and costs.
Since the underground casing does not rotate, the risk of ground collapse is suppressed, and ground stability can be ensured.
Overview of the construction method using a full-rotation machine.
Future Development:
This method will be actively proposed as a rational pile construction method that reduces construction time and costs in urban redevelopment projects where underground obstacles are present. Marugo Kiso Kogyo Co., Ltd. will continue to be responsible for the construction of this method.
Background:
In urban redevelopment projects, the presence of underground obstacles can sometimes prevent the excavation of pile shafts using earth drill machines. Therefore, the conventional "Okumura-Marugo Pull-out Resistance Pile Construction Method (OMR/B-2)" required the removal of underground obstacles interfering with the pile using a full-rotation machine, followed by temporary backfilling with fluidized soil, before constructing enlarged-base piles with an earth drill machine. This involved many steps and presented challenges in terms of construction efficiency.
To address this, both companies added a method that performs shaft excavation, underground obstacle removal, and enlarged-base excavation consistently with a full-rotation machine, and confirmed its effectiveness through full-scale testing. With the expansion of the construction method, the method name was changed to "Okumura-Marugo Enlarged-Base Pile Construction Method (OMR/B-2)" (hereinafter, "this method"), and technical certification (BL Certification - 060) from Better Living was re-acquired.
Added Construction Method Using a Full-Rotation Machine:
After shaft excavation, the casing in the enlarged-base area is pulled out, and the upper casing is set on the full-rotation machine.
The full-rotation machine rotates the upper casing, and its rotational force is transmitted to the Kelly bar by a specialized jig (patent pending).
The OMR/B-2 excavator attached to the bottom end of the Kelly bar rotates and excavates the enlarged base.
Benefits:
When underground obstacles are present, enlarged-base piles can be constructed using a full-rotation machine and a crane, without using an earth drill machine, thereby reducing construction time and costs.
Since the underground casing does not rotate, the risk of ground collapse is suppressed, and ground stability can be ensured.
Overview of the construction method using a full-rotation machine.
Future Development:
This method will be actively proposed as a rational pile construction method that reduces construction time and costs in urban redevelopment projects where underground obstacles are present. Marugo Kiso Kogyo Co., Ltd. will continue to be responsible for the construction of this method.