DE19721269C2 - Process for the production of a foundation structure on a low load-bearing building ground - Google Patents

Description

The invention relates to a method for producing a foundation building works on a low-load-bearing building ground, in which in the low-load-bearing Building ground to the deep, load-bearing building ground vertical support members be inserted, over the heads of a high-strength, slack reinforcement the reinforcement is loaded with at least one layer of earth material and a load-distributing, rigid plate over the earth layer is arranged.

This procedure is used especially when the viable Soil is only present in greater depth and the overlying earth layers are lightly resilient and not interchangeable due to their capacity are.

A method of this type is known from DE 44 07 747 A1. This Scripture shows a railway embankment, the layers with low load-bearing capacity, z. B. floors, peat or fillings. To handle larger loads to be able to transfer the deep, stable building ground are verti kale support members, e.g. B. piles, concrete columns or the like are provided, which are held with their lower ends in the load-bearing building ground and who wear headplates on their upper ends, the tops of which match the Form essentially the top of the low load-bearing floor. At least one reinforcement layer, e.g. B. fleece, Fabrics, grids, mesh, laid with polyolefin plastics. To this Reinforcement layer is a 5 cm thick leveling layer made of sand and above a layer of solidified grain mixture, e.g. B. lean concrete, applied, which forms a load-distributing plate.

The reinforcement position here is essentially horizontal over the Head plates of the support members and over the low-load-bearing building ground relocated so that when compressing the above the reinforcement layer Chen layers due to the elongation caused by large tensile forces Reinforcement layer forms a sag in the reinforcement layer.  

It is known that the low-bearing layers of earth are very thick with various deep foundation processes the burdens in the deep load-bearing building ground. Since this is usually punctiform, e.g. B. through different types of piles, columns and supports, must be used Initiation of area loads then a connection between the pile heads through a rigid plate or through a pile grate getting produced. Such structures are called traffic constructions Moor bridges. This is a rigid, technical and financial one very complex solution, especially for those in between auxiliary structures are required for the pile heads.

It is also known and has been used several times in traffic structures Load entry into the piles and pillars of a deep foundation allow a relatively thick gravel pad (thickness at least equal the column spacing) is built above, in which the vaulted earth forms can. The gravel pad is reinforced with geosynthetic layers. This Solution requires a minimum thickness of the gravel pad equal to the distance of the Piles or pillars. The user is forced to use either the Column spacing to be chosen less than required by the load capacity or the upholstery layer unnecessarily choose you

The invention has for its object the above Improve the process in that the resilience of the reinforcement layer is enlarged.

This object is achieved according to the invention in that the reinforcement designed with surface reserve above the heads of the vertical support members so that it sags like a hammock even at low loads, before the greater exposure to the soil layer takes place.

The burdens from own and traffic loads are load-bearing building ground by means of the vertical support members and with a flat and with a large sag high-strength reinforcement (e.g. Geoplastic reinforcement) as a "hammock", each on the heads of the vertical support members is suspended, transferred so that the low load-bearing capacity against interlayers. The sagging laying  the reinforcement has the advantage that it can take considerably larger loads can without stretching.  

The load is initially transmitted via the load-distributing bending plate, e.g. B. a reinforced one Foundation pad of sufficient thickness. For load entry in the vertical support members is the designed high-strength, sagging reinforcement on the heads of the vertical support members suspended. The sag of this "hammock" forms itself when the high-strength Reinforcement layer designed with the required area reserve and then with a first Soil layer is loaded. The load is transferred to the heads of the vertical support members via the tensile forces in the reinforcement layer. The vertical support members are at a relatively short distance, the spaces are defined by the load-distributing, rigid plate (e.g. reinforced concrete plate or Reinforced foundation pad with bridging vaults).

The foundation structure can be used advantageously in particular when traffic structures over low or non-load-bearing floor layers or other buildings on such a surface are to be founded, whereby the stable building ground is only available in greater depth.

The invention is explained in more detail using an exemplary embodiment. The attached drawing shows the basic structure of the foundation structure.

After the accompanying figure (dead loads and live loads) 1 in the low-lying, load-bearing building 2 is for the transfer of the loads a load-distributing bending plate 4, z. B. a reinforced gravel pad of sufficient thickness with reinforcement layers of geosynthetics 5 applied over the heads 8 of the support members 6 (column heads). To load the vertical support members ( 6 ) with a flat and with a large sag high-strength reinforcement 7 (z. B. geosynthetic reinforcement) a kind of "hammock" is formed, which is suspended from the column heads 8 of the vertical support members 6 . The sag of this "hammock" 7 forms automatically when this high-strength reinforcement is designed with the required area reserve and is then loaded with a first layer of earth material 9 . The load is introduced into the column heads 8 of the vertical support members 6 via the tensile forces in the reinforcement 7 . The vertical support members 6 are at a relatively small distance 10 , the gaps are bridged by the load-distributing bending plate 4 (e.g. reinforced foundation pad or reinforced concrete plate with vaults 11 forming in it).

The process steps are as follows:

• 1. Introduction of the vertical support members 6 into the low-load-bearing building ground 3 to the low-lying, load-bearing building ground 2 .
• 2. Padding of the column heads 8 and laying out a high-strength, sagging reinforcement layer made of geosynthetic 7 , which can hang on the column heads 8 .
• 3. Loading of the respective reinforcement layer hanging in the columns with a gravel layer 9 , which tightens this reinforcement layer and compaction of this gravel layer with a vibrating plate.
• 4. Structure of a rigid plate 4 on the gravel layer 9 . The rigid plate 4 usually consists of a reinforced foundation pad or reinforced concrete. If it is a reinforced foundation pad made of well-graded gravel and geosynthetic reinforcement layers 5 , it is built up in layers with sufficient compaction.

Reference strips List

1

Traffic loads / dead loads

2

load-bearing, deep-lying building ground

3

Intermediate layer of soil (low or not load-bearing)

4

load-distributing bending plate, e.g. B. reinforced foundation pad

5

Reinforcement layers made of geosynthetics

6

vertical support member (column / piles)

7

sagging high-strength reinforcement, geoplastic layer / hammock

8th

Head of the support member (column head)

9

Soil (gravel) layer as a load

10

Distance between vertical support members

11

Erdgewölbe

Claims (6)

1.Procedure for the production of a foundation structure on a low load-bearing building ground ( 3 ), in which vertical supporting members ( 6 ) are introduced into the low load bearing building ground down to the deep, loadable building ground ( 2 ), a high-strength, slack reinforcement ( 8 ) 7 ) is laid, the reinforcement ( 7 ) is loaded with at least one earth layer ( 9 ) and a load-distributing, rigid plate ( 4 ) is arranged over the earth layer ( 9 ), characterized in that the reinforcement ( 7 ) over the heads of the vertical support members ( 6 ) is designed with a surface reserve, so that it sags like a hammock even at low loads before the greater load from the soil layer ( 9 ) takes place. 2. The method according to claim 1, characterized in that a geoplastic reinforcement layer is used as reinforcement ( 7 ). 3. The method according to claim 1 or 2, characterized in that about the first layer of earth as a load-distributing plate is a reinforced foundation padding is applied, which is composed of graded gravel layers and layers of geosynthetics. 4. The method according to claim 3, characterized in that the green man-made cushion made of reinforced layers of gravel is so thick that vaults ( 11 ) supported by the vertical support members form in them. 5. The method according to any one of claims 1 to 4, characterized in that the reinforcement ( 7 ) on the column heads ( 8 ) of the vertical support members ( 6 ) is suspended. 6. The method according to claim 1, characterized in that the rigid plate ( 4 ) consists of reinforced concrete.