PURPOSE: To safely and exactly set shore struts by a method in which an oil- pressure cylinder is slidably set in parallel with the pivotal support shaft of a bucket on the back of the bucket in such a way as to enable the end portion of the cylinder to advance from the side to the outside of the bucket.

CONSTITUTION: An oil-pressure cylinder 9 is contracted, and under the condition, a control trench 16 is excavated between already-driven sheet piles 17. Walings 18 are set and fixed, and a bucket 3 is stopped between the walings 18. Oil- pressure tubes 13 on both sides of the arm 2 are connected, or a three-way valve 20 is operated and the cylinder 9 is driven to advance a flange 10 to the outside of the bucket 3. Whereupon, the right-side flange 10 comes into contact with the right-side waling 18. The cylinder 9 is then slid to the left within the inner cylinder 7, and the left-side flange 10 comes into contact with the left-side waling 18. Under the condition, oil pressure is raised and the walings 18 are pressed on the ground to consolidate it. A shore strut 21 is then set between the walings 18 to support the interval of the walings 18.