DE3037493A1 - SYSTEM FOR INTERMEDIATE SUPPORTING - Google Patents

Description

DR.-ING. AVALTER ABITZ DR. DIETER F. MORF DIPL.-PHYS. M. GRITSCHNEDER patent attorneys

Munich,

3 October 19 80

Postal address Postfach 860109, 8000 Munich 86

Pienzenauerstraße 28 Telephone 98 32 22 Telegrams: Chemindus Munich Telex: CO) 523992

5528-5

ASHFORD SUPPLIES LTD.

942 Brunette Avenue, Coquitlam, British Columbia,

V.St.A.

System for the temporary support of an excavation

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The invention relates to a system for temporarily supporting the excavation surface of an excavation or excavation / to a method for creating temporary support and to a method for facilitating excavation by attaching a temporary support to the excavation area until it is erected . permanent structures.

Considerable excavation for the foundations can be required, especially for the construction of large buildings or the basement of the building become necessary. The areas exposed by the excavation have to be supported because in some cases they go into the construction pit can slide. The ground is an extraordinarily mobile material. When digging a The engineer must assess the construction pit which support effects must be expected from an interconnection system, so that anchors or braces of sufficient length, strength and number are obtained so that the connections are adequate are to ensure the necessary support, and thus sufficient support for the between the anchors or struts guarantee exposed ablation surface is.

Prior art known to the applicant includes U.S. Patents 3,638,435 (Mason, February 1, 1972), 3,802,204 (Mason April 9, 1974) and Reissue 28,977 dated September 28, 1976 on the aforesaid U.S. Patent 3,638,435.

The cited patents describe the production of a retaining wall which is formed by a layer of concrete. An arrangement of rows and columns of dowels and

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Tendons extend from the concrete layer into the embankment held by the retaining wall. The individual elements are held in place by a row of anchor belt girders at the junction of the dowels with the top of the layer the retaining walls together.

The Reissue patent shows that one can access the anchor belt carrier can do without. This patent indicates that under certain circumstances, for example If the ground is sufficiently firm or the excavation is relatively flat, the concrete anchor straps are unnecessary.

Mason always uses compressed air conveyed concrete and also reinforces this concrete layer in any case. Working with compressed air conveyed concrete is costly and requires special skills. The provision of the concrete at the excavation site and the setting time required for the concrete can cause delays in the support of the free floor area and lead to delays in construction planning.

The present invention is intended to provide a support system and a method for erecting a support system that is cheap, that uses material that can be easily stored on site, and that anyway ensures the required mechanical strength. In particular, it is not necessary to use compressed air To use concrete.

According to a first feature, the invention is a system for temporary support in one Excavation, thus a removal area of the excavation is specified during the construction of a permanent structure; this system comprises: (a) a flexible membrane,

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capable of withstanding tensile stress, and (b) a device with which the flexible membrane is fixed to the ablation surface.

The flexible membrane ensures tensile strength, but has little resistance to bending and is used by a regular or irregular grid secured by punctiform or linear supports. About the tension To bring about, through which the membrane causes the support, one must either the sides of the excavation can bulge out between the punctiform or linear supports, or additional material must be used Fill as a packing between the membrane and the cut bottom surface. The membrane can consist of individual Lanes exist, and each individual lane only needs to cover part of the height of the floor cut because of the Protection for the total height is brought about by a sequence of strips arranged one above the other. Where that the If this is the case, to make it easier to attach the packaging material, it may be advisable to use the individual strips that together form the Form membrane, on the respective upper edge at a distance from the ablation surface and on the respective lower edge placed close to the ablation surface. To this In this way, suitable openings are created in the membrane for filling in packing material.

The flexible membrane can be made from a variety of materials or a combination of materials. as A suitable combination has been found: steel mesh mats with strips of fabric or synthetic resin. The steel mesh transmits the forces from the brackets across the surface of the cut ground and the lining layers made of fabric or synthetic resin sheets prevent material from falling through the grille openings. In general steel mesh mats, which are used as concrete

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reinforcement are used and are known, for example, under the trade name Weldmesh, have proven to be useful. The material consists of steel wires that are laid one on top of the other to create a rectangular grid, that is welded or otherwise fixed at the crossing points.

Polyethylene has particularly proven itself as a material for lining sheets. The preferred packing material is sand. Polyethylene sheeting and sand, as well as welded wire mesh, are usually available on construction sites.

All materials listed are only given as examples. The invention only requires that the membrane constituent materials have adequate flexibility and tensile strength and have such a structure that the floor does not slip through. Occasionally one can omit the packing material as dispensable.

If one of the materials forming the membrane consists of individual webs or mats , the connection of the membrane must, if necessary, be established by sufficient overlap at the abutting web or mat edges or by clipping or by other suitable mutual connection above, below or laterally of adjacent webs, including the The manufacturer of the respective materials gives the instructions.

The regular or irregular grid of punctiform supports for the membrane can be created by anchor plates be attached to the free ends of the screwed and cut in the ground surface Tendons are attached; these plates are large enough to take the force from the tendons on the To transfer membrane. The supports can also be designed as struts that are inserted into the excavated

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be held rich or at other supporting structures. The other execution in regular or irregular Lattice arrangement of a linear support for the membrane can be formed by supports that between point supports of the specified type are relaxed.

Another feature of the invention is a method of building a support system for an excavation Securing a cut removal area of the excavation when building a permanent structure; the method consists in making a tensile flexible membrane brought against the floor surface and this membrane is fixed at least at the top and bottom so that it has the tensile stress can accommodate.

A preferred method of forming the membrane is by hanging a sheet of liner over the floor surface and then a gilter mat is attached over it at the intended distance. As the packing material is fed, it pushes the liner sheet against the grid mat, so that both form a membrane with one another.

According to a further feature of the invention is an excavation method characterized in that a first Wandabs.Ghnitt is excavated that a tensile stress-resistant flexible membrane is placed against the first wall section that said flexible membrane on its Place is determined that a second wall section is excavated below the first, that a tensile strength flexible membrane is placed against said second wall section that the flexible membrane is attached their place in the second section is determined that

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further wall sections excavated to the required depth and tension-resistant flexible membranes against these further wall sections, and that a flexible membrane in place in each section is determined before the excavation work for the next lower section.

The regular or irregular network of mounts for the membrane is looked after in a safe and expedient manner Method produced, either following the progressive construction of the membrane or in whole or in part before or after the construction of the membrane.

In the methods described above, there is no need for the liner and mesh panels which together form the membrane intentionally spaced from the ablation surface and the exposed material may bulge place against the membrane. But you can also intentionally put in sand or some other packing material.

Details of the invention are used to explain exemplary embodiments shown in the drawings, which show:

1 shows a cross section through a fuse structure according to the invention;

Figure 2 is a view of the structure of Figure 1;

3 shows a cross section through a further embodiment of the invention;

4 shows a cross section through a further modified embodiment of the invention.

All drawings show a support or safety system

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for an ablation surface 2 and have lattice mats 4, which are at least partially at a distance from the surface 2 can be held so that a gap between the grid mat 4 and the surface 2 is created. In the Surface 2 protrude tension members 6, which hold the wire mesh 4 in the correct position. One example Lining sheet 8 made of polyethylene lies against the grid mats 4 in the free spaces. These rooms are filled with packing material 10, preferably with sand.

Fig. 1 shows an embodiment of the invention, the grid mats 4 at their upper edge at a distance from the surface 2 and at their lower edge close to the surface 2 are held, so that an open top pocket is created, which receives the packaging material 10. With this system the packing material can be easily filled.

According to the drawing, each grid mat 4 overlaps each laterally (Fig. 2) or above (Fig. 1) adjacent mat 4, The Tensioning elements 6 are arranged on the upper and lower edges of the mesh mats 4 in order to fix the mats. Additional tendons can also be used in other places. At the end of each tendon 6 is an anchor plate 12 attached, which improves the definition of the mat 4. In the embodiment according to FIG. 1 there are anchor plates 12 at the lower end of a mat 4 close to the surface 2. In this case, on the same tendon 6 is a second Anchor plate 12 attached, which is further away from the surface 2 and the upper edge of the lower, should hold the overlapping mat 4. The tendons 6 are slanted in for better durability the surface 2 introduced.

The following is to be said about the drawings:

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In Figs. 1, 3 and 4, the upper floor portion is broken off drawn because the upper layer is generally the least stable; often there lies looser or disturbed soil. However, the slope is not absolutely necessary. You can see the entire area from the top up let it run at an incline at the bottom, and if the space conditions permit, this is for the sake of greater security maybe expedient. Fig. 4 shows a slightly sloped total area.

The anchor plates 12 can be horizontal or vertical or diagonally extending supports can be formed. If necessary, a plurality of mats 4 or a plurality Lanes 8 are provided, the respective following lanes or mats being placed on top of the previous one.

According to Fig. 3, the safety structure ends just above the bottom of the excavation. That is permissible if the bottom cut or the excavation ends up in a soil material that is fixed even without support, for example in rock.

If, according to FIGS. 3 and 4, there is little space between the intended permanent building and the floor area, one can work with a single anchor plate 12. This of course makes it difficult to bring in sand, but it saves space.

Fig. 3 shows a modified embodiment in which struts 13 are used instead of tension members 6.

In the manufacture of a section of the security system according to the invention, a lining sheet 8 and a Mesh mat 4 placed against the surface 2, and you can keep a distance from the surface 2, so that a pocket between the web 8 or the mat 4 and the surface 2

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is formed. The packing material 10 is then filled into the pocket between the surface 2 and the web 8.

Fig. 1 shows an excavation method which is as follows expires: Starting at ground level, the floor of the first excavation section is excavated (cf. Fig. 1). In general terms, each section is the height that remains unsecured at least as long as until the support wall according to the invention is attached to it. With stable ground conditions, however, can also the height envisaged by the site manager for other reasons may be chosen, and the largest dimension available may be chosen of the mat 4, minus the required overlap, be decisive.

usually at least the first section is canceled, because, as mentioned, the top soil layer is often unstable. A lining sheet is placed on face 2 of the first Section placed, and a grid mat 4 on the lining mat 8. The upper edge of the mat 4 and the lining sheet 8warden either only by a hook 14 (see. Fig. 1 and 4) or determined in that the upper part is wrapped around a wooden sleeper 16 and this is fixed with a hook (see. Fig. 3). The details of the arrangement on the upper edge depend on whether the upper edge of the Lining sheet an opening is to be formed so that sand and other packing material through the grid and after can be poured at the bottom behind the lining, or whether the packing material, at least at the top, should be left out. The lower part of the lining sheet 8 and the mat 4 are made by driving a tendon 6 into the surface 2 set at the bottom of the first section.

When the first section has been completed, the excavation for the second section, the one after the same, takes place Scheme is treated as above. When executing

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According to FIG. 1, the lining sheet 8 and the grid mat 4 are spaced apart at the upper end of the second section from surface 2, but lie tightly against surface 2 at the lower end of the second section. The tendon 6 am The lower end of the first section also becomes the tendon for fixing the upper part of the lattice mat 4 of the second section. An anchor plate 12 is attached to the tendon or, if necessary, a carrier. The anchor plate 12 is located at the lower end of the second section on the screwed in or driven in Tendon 6. The packing material 10 is then poured into the pocket thus created.

This process is repeated until the required depth the excavation is reached.

The upper edge of the first section can also be held in place by means other than those shown. For example wire rope straps or horizontal girders can be used.

When setting up the security structure, the overlapping mats 4 are preferably with their sides against one another bracketed. The application of brackets around the edges The grid mat lets the tensile strength of the grid arise because the grid is like a coherent one Lattice mat behaves. However, this feature is not indispensable within the scope of the invention. Usually enough a simple overlap and wire connection of the mats at their edges.

The present invention provides an inexpensive but still powerful safety and support system. The tensile strength the welded wire mesh 4 in the preferred embodiment

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represents in connection with the polyethylene sheets 8 a membrane which is sufficiently strong to cover the ablation surface 2 between anchor plates 12 or anchoring beams to keep.

If sand or another packing material 10 is filled between the membrane and the surface 2, it develops the strength of the membrane and transfers the sustained pressure to the surface 2. The granular material 10 allows free Drainage during construction and represents a filter zone that allows the permanent, free penetration of sludge Prevents backfilling from draining around the finished structure.

In contrast to strong woods, which are sometimes used to support an erosion surface between beams, the materials used in the present invention do not lose volume _t when they weather over time. They can therefore remain in place = · without having to fear that cavities will subsequently arise in the earth surrounding the building.

In contrast to walls made of concrete, the membrane used according to the invention has its full strength immediately after their application.

End of description.

Claims (29)

1. System for the temporary support of an excavation during the construction of a permanent structure to retain an erosion area of the excavation, characterized by (a) a flexible membrane that can withstand tensile stress, and (b) a device with which the flexible membrane is fixed to the ablation surface (2). 2. System according to claim 1, characterized in that the flexible membrane consists of metal mesh (4), the is lined with a lining sheet (8) to prevent material from falling through the grid (4). 3. System according to claim 2, characterized in that the metal grid (4) is designed as a straight steel wire grid is whose wires are welded together at their crossing points. 13 CTO ¹ IS "/ 09 18 5528-5 ^ 4. System according to claim 2, characterized in that the lining sheet (8) consists of polyethylene. 5. System according to claim 1, characterized in that the tensile strength of the membrane is developed in that the ablation surface (2) is against the outside the membrane can move. 6. System according to claim 1, characterized in that the tensile strength of the membrane by filling in packing material (10) is developed between the membrane and the ablation surface (2). 7. System according to claim 6, characterized by gaps which are formed to allow the packing material to be filled (10) to facilitate. 8. System according to claim 6, characterized in that sand is used as packing material. 9. System according to claim 1, characterized in that the means for fixing the flexible membrane comprises tendons (6) on the removal surface (2), which are driven into the ablation area (2), and that at the outer end of each tendon (6) anchor surfaces (12) are attached. 10. System according to claim 1, characterized in that 13 0 016/0910 5528-5 X the device for fixing the flexible membrane on the ablation surface (2) a plurality of struts (13) which extend outwardly from the surface (2) and hold the flexible membrane in place. 11. System for the temporary support of an excavation during the construction of a permanent structure to retain an erosion surface (2) of the excavation, characterized by Support webs which are held at least partially at a distance from the surface (2), so that a gap between the support track and the surface (2) is created, a device that the support tracks in the required Position holds, a lining sheet (8) held against the support sheets in the space, wherein the support sheet and the liner sheet together form a flexible membrane which can withstand the tensile stress, and characterized by
Packing material (10) in the space. 12. System according to claim 11, characterized in that the support webs comprises straight steel wire mesh, the wires of which are welded to one another at the crossing points are. 13. System according to claim 11, characterized in that the individual support tracks at their upper end with Distance from the surface (2) and at its lower end close to the surface (2) are kept, so that a A pocket open at the top is created. T30016 / 0916 5528-5 .ty 14. System according to claim 11, characterized in that the means holding the support webs in place holds, is formed by tendons (6) which protrude into the ablation surface (2) and at each Tensioning member (6) have anchor plates (12) which are used to keep the supporting webs plagued. 15. System according to claim 11, characterized in that each support track the respective side or above lying web overlaps. 16. System according to claim 13, characterized in that the tendons (6) in the vicinity of the upper and the are arranged at the bottom of the support webs in order to set them. 17. System according to claim 11, characterized in that the means holding the support webs in place holds, is formed by struts (13) which protrude from the surface (2) to the outside. 18. System according to claim 13, characterized in that carriers serve as anchor plates. 19. System according to claim 15, characterized in that the same tendons (6) are used to define the lower edge of an upper, overlapping support sheet and the upper edge of a lower overlapping support sheet. 130016/0918 5528-5 .ζ. 20. System according to claim 11, characterized in that the lining sheet (8) consists of polyethylene. 21. System according to claim 11, characterized in that sand is used as packing material (10). 22. Method of erecting a temporary support system for an excavation to be carried out during construction of a permanent structure to hold back a removal area of the excavation, characterized in that that a flexible membrane, which withstands the tensile stress, is fixed to the surface (2), and that the flexible membrane is set at least at its upper and lower end so that it is in the Is able to withstand the tensile stress. 23. The method according to claim 22, characterized in that the flexible membrane made of steel mesh with inlaid Lining sheet (8) is made on the surface (2). 24. The method according to claim 22, characterized in that the flexible membrane by driving in tendons (6), which are provided at their outer end with anchor plates (12), set in the removal surface (2) will. 25. The method according to claim 22, characterized in that the flexible membrane by setting up struts (13) - 5 130016/0918 5528-5 .fg. is determined from the ablation area (2) facing outward and touching the pliable membrane to hold it in place 26. The method according to claim 23, characterized in that the packing material (10) between the removal surface (2) and the flexible membrane is filled. 27. Method for excavation, characterized by the following steps: Excavation of a first wall section, attachment of a flexible membrane, the tensile stresses withstands, on the first wall section, fixing said flexible membrane in place and Job, Excavation of a second wall section below the first, Attaching a flexible membrane that can withstand tensile stresses to said second wall section, Fixing said flexible membrane in place, Production of further wall sections to the required depth and attachment of flexible membranes, withstand the tensile stresses on those other wall sections, and Attach a pliable membrane in place on the particular ablation surface before moving on to the deeper located section passes. 28. The method according to claim 27, characterized in that a lining sheet (8) is placed against the surface to define the flexible membrane, and that one 1 3 0X)% 6V 0 916 5528-5 1 The support sheet is placed against the lining sheet (8) and this support sheet is fixed in place, and that the support sheet and the lining sheet (8) together form the flexible membrane. 29. The method according to claim 28, characterized in that a packing material (10) between the surface (2) and the flexible membrane is filled. 1 3 0 Ö 1 ⁷ 6 7 0 9 1 θ