A method for manufacturing a one-piece element defining a lost formwork for forming drill guides, includes mixing a volume of hydraulic binder including a first volume of water and a second volume of a bonding element and a volume of an organic base; molding to obtain a one-piece element including at least one cylindrical portion with a radius of at least 40 cm; drying the mixture molded forming a one-piece element, and recessing a central portion of material of the one-piece element in a central zone of the cylinder portion to form a guide.

A method for manufacturing a one-piece element defining a lost formwork for forming drill guides, includes mixing a volume of hydraulic binder including a first volume of water and a second volume of a bonding element and a volume of an organic base; molding to obtain a one-piece element including at least one cylindrical portion with a radius of at least 40 cm; drying the mixture molded forming a one-piece element, and recessing a central portion of material of the one-piece element in a central zone of the cylinder portion to form a guide.

Provided is a variable-pitch wall forming device for a press-fit type underground diaphragm wall, comprising a wall shoe (3), vibration chambers (4), a fixed-pitch box (1) and a variable-pitch box (2), wherein the variable-pitch box (2) is installed in the fixed-pitch box (1), the wall shoe (3) is installed on the bottom of the variable-pitch box (2) and the fixed-pitch box (1), and the vibration chambers (4) are provided on a side wall of the fixed-pitch box (1) and a side wall of the variable-pitch box (2). Also provided is a method of variable-pitch wall forming for a press-fit type underground diaphragm wall.

Provided is a variable-pitch wall forming device for a press-fit type underground diaphragm wall, comprising a wall shoe (3), vibration chambers (4), a fixed-pitch box (1) and a variable-pitch box (2), wherein the variable-pitch box (2) is installed in the fixed-pitch box (1), the wall shoe (3) is installed on the bottom of the variable-pitch box (2) and the fixed-pitch box (1), and the vibration chambers (4) are provided on a side wall of the fixed-pitch box (1) and a side wall of the variable-pitch box (2). Also provided is a method of variable-pitch wall forming for a press-fit type underground diaphragm wall.

An end point closing wall forming device of an extrusion type underground diaphragm wall comprises a main body (1) and a vibration water spraying device. The vibration water spraying device is fixedly disposed inside the main body (1). The end point closing wall forming device of an extrusion type underground diaphragm wall further comprises a separation device. The separation device is movably sheathed on the outer side of a short edge (11) of the main body (1). Also provided is a method for operating an end point closing wall forming device of an extrusion type underground diaphragm wall.

An end point closing wall forming device of an extrusion type underground diaphragm wall comprises a main body (1) and a vibration water spraying device. The vibration water spraying device is fixedly disposed inside the main body (1). The end point closing wall forming device of an extrusion type underground diaphragm wall further comprises a separation device. The separation device is movably sheathed on the outer side of a short edge (11) of the main body (1). Also provided is a method for operating an end point closing wall forming device of an extrusion type underground diaphragm wall.

A method of forming a sheet pile wall comprising cold reforming a Z-shape pile or a U-shape pile and connecting a plurality of reformed steel piles so as to form a sheet pile wall having at least one engagement section, the engagement section when viewed in a cross section being a recess that has a narrowed neck portion.

A method of forming a sheet pile wall comprising cold reforming a Z-shape pile or a U-shape pile and connecting a plurality of reformed steel piles so as to form a sheet pile wall having at least one engagement section, the engagement section when viewed in a cross section being a recess that has a narrowed neck portion.

The invention relates to a method for forming a support wall in the ground from a soil mortar which is made in the ground by mixing soil material and a cement suspension, wherein vertically directed support beams comprising a structural steel are set into the soil mortar in the ground prior to curing, and after curing, soil material is removed along an upper support wall section on at least one side of the support wall, while a lower support wall section continues to be surrounded by soil on both sides. According to the invention, it is provided that a thin-walled sheathing element from concrete is attached to at least one support beam, which extends along an upper support beam section, and that the support beam is set into the soil mortar in such a way that the upper support beam section with the sheathing element from concrete extends along the upper support wall section.

Apparatus and methods for the installation of pipe pilings into the ground for use as structural building foundations, geothermal piles, or both, are disclosed. In addition to specialized fittings for pipe pile assemblies, the inventions include specialized drive mechanisms used in conjunction with rotary or vibratory motors. Methods of installing pipe pilings are further improved with the disclosure of methods of adding grout or similar materials during or after installation of the piles.