DE19739106C1 - Construction method for foundations etc. in water-filled excavation - Google Patents

Abstract

The method uses a floating caisson with base (7), side walls (9), reinforcements and anchors (8) of steel. This is assembled on dry land, inserted watertight and floating into the excavation, lowered continuously or in stages, and then anchored in the side walls near the base (6) of the excavation. Base and/or side walls are reinforced with concrete. Anchoring is via a pref. horizontal anchor ring of steel.

Description

The invention relates to a method for producing a civil engineering structure in a Groundwater-filled underground pit using a floating Lowering body according to the preamble of claim 1 or 2. Such methods are used in areas where the groundwater level is high and a Lowering the groundwater is not possible or is not necessary.

For the production of buildings below the surface of the site (civil engineering) there are also for high groundwater levels a variety of proven methods of Civil engineering, the most important of which are listed below.

Are known:

• - The diaphragm wall construction technique, with the special strip-shaped excavation and Concreting process completely the outer wall of a civil engineering structure without an excavation pit will be produced. This is followed by excavation of the civil engineering structure and under water Concreting the floor with the side wall according to various known Methods is connected.
• - The process of lowering groundwater. This is done by groundwater lowering caused drainage of the construction pit a civil engineering structure according to known Civil engineering processes, usually in reinforced concrete.
• - The caisson process, in which a caisson made of concrete or Steel with the dimensions of the civil engineering body is produced. This caisson can be made with a closed bottom and / or closed ceiling. The The caisson is lowered by excavating the soil inside the caisson using various known methods and controlled lowering of the caisson due to heavy weight. With a closed caisson, the bottom in the Overpressure processes are dug out.
• - For the production of special hydraulic structures are procedures with floating Caissons are known in which the buoyant caisson is made of concrete or steel is manufactured outside the building site and is floated to the building site in order to to be lowered there and further processed, for example as a pillar for Bridge works.  
• - The lowering process, in which ring-shaped concrete or steel walls in Gravity processes are lowered in the context of continuous Excavation of the soil inside. These have ring walls on the underside cutting-like shapes, which causes subsidence during the lowering process be avoided.
• - DE 42 19 078 A1 describes a method according to the preambles of claims 1 and 2 known. There a formwork panel is hung on piles. On the Formwork panel is then made by concreting individual sections at the same time Lowering the civil engineering works. The disadvantage here is that with the introduction of Technical and related piles and the hanging of the civil engineering structure on the piles Expenditure.

The above methods have one or several of the following shortcomings or disadvantages: high costs, lowering of groundwater, lack of watertightness, problems with lowering up to misalignment and Get stuck.

Proceeding from this, the object of the invention is a simple, inexpensive one To create a process in which the civil engineering after the empty pumping is securely anchored against buoyancy against the earth and Water pressure is statically safe and tight.

This object is by the in the characterizing part of claim 1 or Features contained claim 2 solved.

A support wall, straight or, is made using the usual methods of pile driving curved, for example circular. The sheet piles are through Fall ramming, shaking and swinging, pressing, with or without pre-drilling into one Sheet pile joined together, which has the contour of the future civil engineering structure, however, it has a larger internal width than the outer dimensions of the civil engineering structure. The sheet pile is placed so deep in the ground that after excavation of the Ground inside to the required depth of the pit still sufficient in the ground is anchored. The upper edge of the sheet pile wall is expediently covered by a Fastening ring, for example a steel ring or concrete ring, anchored. So that will the external earth pressure is completely absorbed by the sheet pile wall.

After excavating the soil from the excavation pit specified by the sheet pile wall to the intended depth with the groundwater level kept constant Floating mounting of the steel lowering body, which is the shape of an all-round  reinforced square or round container. The assembly can take the form prefabricated floating floor sections made of steel in the filled with water Excavation take place, on which then the side wall sections up to the full height of the lowering body. To limit the free mounting height, you can in between, d. H. after assembling some side wall ring sections, subsidence of the floating sinker, e.g. B. by ballast water. Another installation option is that the lowering body on land Manufacturer or next to the site largely or completely assembled and with Hoists or otherwise placed in the construction pit filled with water, lowered and, if necessary, fully assembled.

The floating and lowered after completion sinking body can both in Bottom as well as in the side wall area be reinforced by concrete, which with the Sheet pile wall is connected by anchorages.

Preferably, the floating lowering body receives around the outside at the level of Suitable horizontally arranged container bottom and stiffened with the side wall Anchor ring plates in the width of the gap between the sinker and the sheet pile wall. After lowering the lowering body and aligning the lowering body in the The sinker is anchored to the sheet pile wall via the excavation pit Anchor ring by underwater welding, underwater concrete, etc. The gap between the sheet pile and the sinker is filled and that Filling material compacted.

In a preferred embodiment, the lowering body is in the area of the terrain surface connected and anchored to the sheet pile wall by a reinforced concrete ring.

From the lowering body secured against the existing buoyancy, this can be done in groundwater located in its interior are pumped out, with which waterproof civil engineering is completed.

Embodiment

The invention is illustrated by drawings that show an embodiment, explained. In the example, a circular civil engineering structure, e.g. B. for underground garages or Storage purposes.

Fig. 1 shows a section of a site with terrain surface ( 1 ), the groundwater level ( 2 ) and a set circular sheet pile ( 3 ) with an upper fastening supply ( 16 ). The soil material has been partially removed from the excavation pit ( 4 ) ( 5 ).

Fig. 2 shows in section the arrangement of the circular sheet pile wall ( 3 ) around the fully excavated excavation pit ( 6 ) with a clear diameter that is larger than the outer diameter of a lowering body ( 7 , 8 , 9 ) made of steel, whereby between the civil engineering structure and a gap ( 17 ) is formed in the sheet pile wall. The figure shows an intermediate assembly state of the lowering body, which floats in the groundwater ( 2 ), consisting of a steel base plate with floating body ( 7 ), an anchor ring made of steel ( 8 ), wall sections ( 9 ) made of steel, a concrete reinforcement ( 10 ) of the steel outer wall and a concrete filling in the float ( 11 ).

Fig. 3 shows a section of the completed, lowered to the bottom of the excavation pit, which consists of steel with concrete reinforcements, including in the form of sub-floor concrete ( 12 ) and interior floor concrete ( 13 ). The gap between the sheet pile wall and the lowering body is filled with material ( 15 ), which was then compressed. The sheet pile wall is connected to the lowering body at ground level ( 14 ).

Reference list

1

Terrain surface

2nd

Groundwater level

3rd

Construction pit enclosure, e.g. B. sheet pile

4th

Bottom of the excavation pit

5

Excavation

6

Floor of the finished construction pit

7

Steel base plate with floating body

8th

Steel anchor ring

9

Side wall or side wall section of the lowering body made of steel

10th

Concrete reinforcement of the steel outer wall

11

Concrete filling in the float

12th

Subfloor concrete

13

Interior floor concrete

14

Upper anchor

15

filling material

16

Upper mounting ring

17th

Gap between sheet pile wall and lowering body

Claims (8)

1. A method for manufacturing a civil engineering structure in a partially or completely filled with groundwater ( 2 ) underground pit using a floating sinker, the walls of the underground pit being secured by known trench enclosures ( 3 ) such as sheet piling or the like, characterized in that the one Floor ( 7 ) made of steel, side walls ( 9 ) made of steel and reinforcements and anchors ( 8 ) made of steel lowering body is mounted on land, then is inserted into the underground pit in a watertight floating manner, is lowered continuously or gradually after completion of the operation and is at the level of Ground ( 6 ) of the underground pit is anchored. 2. A method for producing a civil engineering structure in a partially or completely underground mine ( 2 ) filled with underground walls, the walls of which are secured by known construction pit enclosures ( 3 ) such as sheet piling or the like, using a lowering body which is constructed in a floating manner in sections, characterized in that that
a prefabricated floating floor section ( 7 ) made of steel is inserted into the underground pit,
that side wall sections ( 9 ) made of steel are placed on the bottom section ( 7 ) up to the full height of the lowering body, optionally with intermediate lowering of the lowering body,
that the lowering body is finally lowered after its completion and anchored at the level of the underground pit. 3. The method according to claim 1 or 2, characterized in that the bottom ( 7 ) or the bottom portion ( 7 ) and / or the side walls ( 9 ) are reinforced with concrete, the concrete with the bottom ( 7 ) or the Side walls ( 9 ) is anchored. 4. The method according to any one of claims 1 to 3, characterized in that the anchoring of the lowering body provided on the wall of the underground excavation is provided at the level of the bottom ( 6 ) of the underground excavation. 5. The method according to claim 4, characterized in that the anchoring is formed by means of a, preferably horizontal, steel anchor ring ( 8 ) which is arranged on the outside of the lowering body. 6. The method according to any one of claims 1 to 5, characterized in that the lowering body in the lowered state in the area of the terrain surface ( 1 ) is connected to the wall of the underground pit. 7. The method according to any one of claims 1 to 6, characterized in that a gap ( 17 ) is present between the wall of the underground pit and the lowering body and that this gap ( 17 ) is filled with bulk material ( 15 ) after completion and lowering of the lowering body . 8. The method according to claim 6 and 7, characterized in that the connection provided in the area of the terrain surface ( 1 ) by means of a reinforced concrete ring ( 14 ).