Abstract: A construction apparatus having an extendable mast with an upper mast element longitudinally displaceable relative to a lower mast element. A linear drive displaces the mast elements relative to each other, and has an upper drive part linearly actuable relative to a lower drive part of the linear drive, and a locking device for locking the two mast elements in an extended mast position. The upper drive part is fixable to the upper mast element, the lower drive part of the linear drive is displaceable longitudinally of the lower mast element and a securing device is provided on the lower mast element, with which the lower drive part is releasably securable to the lower mast element for displacement of the upper mast element. A method for operating a construction apparatus with an extendable mast can be carried out with a construction apparatus in accordance with the invention.

Abstract: The present invention relates to a shuttering element for limiting a section of a trench wall. The shuttering element is characterized by a plurality of shuttering parts which have a plate-shaped base body, consisting of concrete in particular, and are connected to one another at their adjoining horizontal front faces. Furthermore, the invention relates to a shuttering part as well as a method for producing a trench wall in the ground.

Abstract: A drilling rig and a drilling method, in which the drilling element is caused to rotate and is displaced along a mast by means of a drilling drive, which drilling element has a continuous screw auger disposed below the drilling drive, and an extension, which is connected to the continuous screw auger and extends upwardly through the drilling drive. A displacement head is disposed between the continuous screw auger and the extension and is adapted to force earth material into the wall of a bore hole.

Abstract: The invention relates to a construction apparatus comprising a base carrier, a mast which is arranged on the base carrier in a pivotable manner, a first hydraulic cylinder and a second hydraulic cylinder for erecting the mast, which are connected to each other in an articulated manner in a connecting section, the first hydraulic cylinder being linked to the base carrier and the second hydraulic cylinder being linked to the mast, and a coupling rocker-arm which is linked on one side to the mast and on another side to the connecting section. According to the invention in the part of the connecting section a spacer is arranged, through which the connecting section is supported on the mast in a detachable manner.

Abstract: The invention relates to a construction apparatus comprising a base carrier, a mast which is arranged on the base carrier in a pivotable manner, a first hydraulic cylinder and a second hydraulic cylinder for erecting the mast, which are connected to each other in an articulated manner in a connecting section, the first hydraulic cylinder being linked to the base carrier and the second hydraulic cylinder being linked to the mast, and a coupling rocker-arm which is linked on one side to the mast and on another side to the connecting section. According to the invention in the part of the connecting section a spacer is arranged, through which the connecting section is supported on the mast in a detachable manner.

Abstract: The invention relates to a construction apparatus having an extendable mast with an upper mast element and a lower mast element, whereby the upper mast element is longitudinally displaceable relative to the lower mast element. The apparatus according to the invention is designed with a linear drive for displacement of the two mast elements relative to each other, whereby the linear drive has an upper drive part which can be actuated in a linear manner relative to a lower drive part of the linear drive, and with a locking device for locking the two mast elements in an extended mast position.

Abstract: The invention relates to a drilling rig and a drilling method, in which the drilling element is caused to rotate and is displaced along a mast by means of a drilling drive, which drilling element has a continuous screw auger disposed below the drilling drive, and an extension, which is connected to the continuous screw auger and extends upwardly through the drilling drive. According to the present invention, a displacement head is disposed between the continuous screw auger and the extension and is adapted to force earth material into the wall of a bore hole.

Abstract: The present invention relates to a shuttering element for limiting a section of a trench wall. The shuttering element is characterized by a plurality of shuttering parts which have a plate-shaped base body, consisting of concrete in particular, and are connected to one another at their adjoining horizontal front faces. Furthermore, the invention relates to a shuttering part as well as a method for producing a trench wall in the ground.

Abstract: The invention relates to a device for making a trench wall in the soil comprising a frame, at least one lower cutting/mixing wheel arranged at the bottom of the frame, at least one further, upper cutting/mixing wheel arranged at the top of the frame, wherein the frame is designed in an intermediate portion between the upper cutting/mixing wheel and the lower cutting/mixing wheel with a smaller cross section with respect to the cutting cross section of the at least one lower cutting/mixing wheel. The invention further relates to a method for making a trench in the soil by means of such a device.

Abstract: The invention relates to a method for sinking a borehole in the ground, in which a wet boring tool with a removal area for producing or advancing a borehole is used, the borehole is at least partly filled with a fluid and in the borehole is formed a filling area and the removal area is at least partly washed round by a fluid flow, which conveys the bore smalls produced at the removal area to a collecting container located in the borehole. The method according to the invention is characterized in that the wet boring tool has a pumping mechanism through which fluid from the filling area is made to flow and conveys bore smalls produced into the collecting container. The invention also relates to a wet boring tool and to a boring plant.

Abstract: The invention relates to a method and a test setup for determining the bearing behaviour of displacement piles. The displacement piles are produced by making a hole using a displacement head and subsequently filling the hole with a hardenable suspension, whilst leaving the displacement head in the hole. The resulting test pile is subject to the action of a test load using a loading device and the bearing behaviour is measured by a measuring device. An efficient test performance results from the fact that the displacement head is introduced into the ground by means of a metallic pile string, which forms part of the test pile.