HK1023798B - Shuttering element for an underground cast wall and method for the removal thereof - Google Patents

Description

The invention relates to a forming element of a flat-wall forming with means for displacing or splitting adhesive concrete masses and rolling concrete in the sectional manufacture of a slit wall.

Slit walls are an important component of the basic structure and serve, for example, as a construction trench enclosure, a support wall for embankments or a sealing wall for dams and landfills. The design of slit walls is characterised by the constant stabilization of an open ground slit by means of a refill of supporting slit. The construction of the slit walls is known to be done in stages, each section forming a concrete unit. The slit wall sections are usually separated from each other by retaining walls. In the past, the retaining walls used were steel slit pipes, which were recovered after the concrete had been stiffened, i.e. the pipe could not be maintained by pulling until the concrete was untied. In recent years, the use of flat-wall formwork, which is only removed after the concrete has been bonded and without the use of a tension press, has been adopted as a formwork, but since, especially in deep-slot walls, due to unevenness and static fluid pressure in the raised wall, liquid concrete runs behind the joint formwork, so-called circulating concrete, in many cases a considerable effort has to be made to remove the formwork from the finished slotted wall area.

EP 0 101 350 describes a process and device for removing the formwork in the manufacture of an underground slit wall. This is a process for removing a formwork element used in the manufacture of a sheet which is part of a wall cast in the ground, the formwork element being a central profile part, the profile of which corresponds to a depression to be formed into the end of the sheets to be manufactured, and having two flanges on either side of the central part. The process is characterised by the following steps: Use a forming element of the above type, projecting over the surface of the floor;mount a tool on the upper part of the forming element, the tool having a body and two profiled parts, forming laterally sliding nuts on the flanges of the forming element, the lower part of the profiled parts being attached in such a way as to form a clearance part;apply a ram movement to the tool in such a way that the wedge-shaped areas of the profiled parts are pressed between the concrete slab and its associated forming element until the wedges are introduced between the concrete slab and the forming element;continue the ram movement to make the tool always deeper until the complete clearance of the forming element is completed.

A tool for this process is characterised by having a body and two profiled parts which form lateral nuts sliding on the flanges of the forming element, the bottom of the profiled part being attached in such a way as to form a discharge shaft.

EP 0 374 051 B1 describes a formwork for the terminal connecting point of a section of a slit wall, consisting of a plate and a box mounted on it, having a longitudinal connecting point in the cross section and consisting of at least two parts, and fitted with connecting elements for the subsequent longitudinal connection, characterised by the box being partly repositioned against a corresponding end of the plate and the connecting elements being formed by a connecting piece having essentially the same cross section as the plates and connecting to the plates concerned by means of a connecting section, which is inserted into the sub-section of the box, as if it were the end of the plates.

EP 0 402 247 B1 describes a process and device for removing a seal attached to the concrete of a section of wall cast into the ground.

Furthermore, DE-U-90 01 679 describes a forming element of a flat-wall forming with means for stamping the forming element from the reinforcing concrete in the sectional manufacture of a slit wall, where the base of the forming element has longitudinal recesses arranged on the sides of the concrete, in which hydraulically or pneumatically operated pistons are arranged, the surfaces of which, facing the concrete, seal the recesses.

The purpose of the invention is to specify a new moulding element of a flat-bottom moulding with means for the removal or sputtering of adhesive concrete masses and in particular of circulating concrete in the sectional manufacture of a slit wall, and a rational method for its expansion, which, compared with known means and methods, are characterized by particular efficiency and uncomplicated handling in the removal or sputtering of concrete masses and thereby promote construction progress and better overcome the difficulties arising from sealing of slit wall sections and facilitate the course of work.

To solve the problem, for a forming element of the type described in the general notion of claim 1, the invention proposes that the release agents are designed in the form of a dispersion device and that the forming element has a base body with surface parts forming concrete guides arranged vertically on each side, between which a U-shaped plane, the back of which is in a continuous line with the concrete mass, is placed in the cross section to accommodate the dispersion device with a vertical pressure body formed in a continuous line in a horizontal direction between the surface parts of the guides forming these guides.

The use of a spreader makes it much easier to separate a flat-bottom forming from the concrete being formed, avoids the use of impact and thus avoids increased wear and vibration and noise on the construction site. Working with the spreader to be used in accordance with the invention allows rapid progress in the smooth handling of the spreader and the associated flat-bottom forming and at the same time contributes to the humanization of the work process.

The design of the moulding element shall be adapted to the requirements.

A process for developing a formwork, which can be assembled from formwork elements, is characterised by the following steps: a spreader or a connected unit of several spreader bodies, for example in the form of a spreadable print strip, with a lifting device, is inserted from above into at least one vertical passage of a flat-bed frame,preferably by spraying the feed frame from the concrete coming up,preferably from above downwards,and after the flat-bed frame has been sprayed,the entire frame is finally removed from the concrete frame and extended upwards.

Further details, features and advantages of the invention are given in the following illustration of an example of an embodiment, shown in the drawings. FIG.1 a view of a slit wall under construction using a forming element of the invention;FIG.2 a slit wall with flat-wall forming according to FIG.1 after the concrete mass has been released by the impact of the sliding device under view;FIG.3 several sliding bodies in conjunction with a lifting device in side view, connected to each other to form a unit of a sliding type.

Figure 1 shows a forming element of a flat-bottom forming 8 with means for displacing or splitting adhesive concrete masses 10 and (not shown) of rolling concrete in the sectional manufacture of a slit wall. The forming element has a base 1 with 2 surface parts 3 forming a surface area 3 with concrete side and vertical guiding elements 2 arranged, between which a horizontal plane x-x U-shaped, with its back formed and force-operated on the axis 10 of the forming, is arranged in a horizontal plane, with the back formed and force-operated on the axis 10 of the forming, for the purpose of absorbing a pressure spreader 4 with a vertical throughput 5 formed pressure spreader 6 in a horizontal direction between the surface parts 3 of the guide element 2 and these splitting elements. The forming element is loosely arranged together with a base 4 in the horizontal direction of the forming element 8 and the base 6 in the horizontal direction of the forming element 1 and the other side of the forming element 4 is designed to integrate the force spreader 1 into the horizontal structure of the forming element 8 and the other side of the forming element 6 is designed to be able to be integrated into the base 4 or 6 of the forming element.

For this purpose, Figure 2 shows the base 1 or the forming element 1 after the removal or release of adhesive concrete masses 10, with the base 1 moving to the right with the integrated transverse wall against the excavation 11 of the next section.

To this end, Figure 3 shows a favourable design of the invention, whereby several spreader bodies 4 are preferably connected together in combination with a lifting device 12 to form a unit 9 in the form of a footprint slide.

According to the invention, the spreading device 4 may be a hydraulic or pneumatic piston/cylinder unit.

The forming element of a flat-wall forming 8 according to the invention is particularly suitable for use in the construction of a slit wall and for the progression in stages by installing a forming element 8 which can be assembled from forming elements according to claims 1 to 6, thus solving the initial task in an optimal way.

Claims (7)

1. Formwork element of a flat joint formwork (8) comprising means for releasing or stripping the latter from adhering concrete masses (10) and also from circulating concrete during the section-by-section construction of a diaphragm wall, characterized in that the releasing or stripping means are designed in the form of an expanding device (4), and in that the formwork element has a basic body (1) with surface parts (3) which form vertical guiding elements (2) and are arranged on the concrete side, between which surface parts (3) a pressure member (6), which is U-shaped in the section of a horizontal plane (x-x), has its rear bearing in a form- and force-locking manner against the concrete mass (10) and is designed with a vertical opening (5) for the purpose of receiving the expanding device (4), is arranged in such a way that it can be displaced in the horizontal direction between the surface parts (3) of the guiding elements (2), in form-locking engagement with the latter.
2. Formwork element according to Claim 1, characterized in that, together with an expanding member (4) which can be inserted loosely from above, it is designed as an integral functional unit of the flat joint formwork (8).
3. Formwork element according to Claim 1 or 2, characterized in that the expanding device (4) is designed on the one hand with its horizontal shaft bearing in a force-locking manner against the basic body (1) of the flat joint formwork (8), and on the other hand against the inner wall of the pressure member (6), for stripping the formwork element or basic body (1) from adhering concrete mass (10).
4. Formwork element according to one or more of Claims 1 to 3, characterized in that a plurality of expanding members (4), preferably in interaction with a lifting device (12), are connected to one another to form a unit (9).
5. Formwork element according to one or more of Claims 1 to 4, characterized in that the expanding device (4) is a hydraulic or pneumatic piston/cylinder unit.
6. Formwork element according to one or more of Claims 1 to 4, characterized in that the expanding device (4) is designed with an electromechanical spindle drive.
7. Method for dismantling a flat joint formwork (8) which can be composed of formwork elements and is designed according to Claims 1 to 6, characterized by the following work steps:

   - an expanding member (4) or a continuous unit of a plurality of expanding members, for example in the form of an expandable ejector carriage (9), is introduced by a lifting device from above into in each case at least one vertical opening of a basic body (1) of a flat joint formwork,

   - basic bodies (1) of the flat joint formwork are successively stripped from the in situ concrete (10), preferably from the top downwards, by expanding the expanding member or members,

   - after stripping the basic bodies (1) of the flat joint formwork from the concrete (10), the complete flat joint formwork (8), including the pressure member or members (6), are withdrawn upwards out of the diaphragm wall and dismantled.