Abstract: The present invention, the objective of which is to provide a pile connecting structure of high workability capable of connecting upper pile and lower pile to each other simply and accurately, and preventing the pile diameter from becoming a large diameter even at this connecting portion, concerns a pile connecting structure for connecting upper pile and lower pile to each other, by interposing a connecting plate of about the same diameter as the piles, at the connecting portion between the upper pile and the lower pile, wherein the end plate of either one of the upper pile or lower pile and the connecting plate are fixed by screwing bolts inserted in circular-shaped bolt inserting holes formed in the connecting plate to the bolt hole in the end plate of the pile on one side, and the end plate of the other pile and the connecting plate are fixed, in the state where the head of the bolts screwed to the end plate of the pile on the other side is inserted in the large diameter portion of heteromorphic bolt inser

Abstract: A method of constructing foundation piles provides improved hole stability and bearing characteristics. A boring a hole is initially formed by drilling. A horizontal pressure is then applied to the inner walls of the hole over a vertical portion of predetermined height until a desired degree of compression is attained. Horizontal pressure is then applied over a subsequent vertical portion of an inner circumferential surface of the hole vertically adjacent to a vertical portion pressed in a preceding step of applying horizontal pressure. The steps of compression are continued until a contiguous vertical expanse of the hole is compressed to a desired degree. Alternatively, the depth of the hole may be increased sequentially following a compression operation, and the subsequently formed hole depth then horizontally compressed.

Abstract: A method of determining capability and quality of a foundation pile and a method of designing the foundation pile comprises the following steps: positioning a ground charcteristics analyzer in a bored hole where the foundation pile is constructed; displacing the surrounding ground of the bored hole; and measuring the force applied to a bored hole and the induced displacement; so that the characteristics and quality of soil and the pile can be analyzed simultaneously with executing the construction. A ground characteristics analyzer with which the above-mentioned methods are performed comprises a horizontal pressing device which protrudes in the radial direction from the outer peripheral of the body of the analyzer to displace the surrounding ground of a bored hole and a vertical depressing device which protrudes downward to deform the bottom ground of the bored hole.

Abstract: A method of determining capability and quality of a foundation pile and a method of designing the foundation pile comprises the following steps: positioning a ground characteristics analyzer in a bored hole where the foundation pile is constructed; displacing the surrounding ground of the bored hole; and measuring the force applied to a bored hole and the induced displacement; so that the characteristics and quality of soil and the pile can be analyzed simultaneously with executing the construction. A ground characteristics analyzer with which the above-mentioned methods are performed comprises a horizontal pressing device which protrudes in the radial direction from the outer peripheral of the body of the analyzer to displace the surrounding ground of a bored hole and a vertical depressing device which protrudes downward to deform the bottom ground of the bored hole.