DE10330963A1 - Foundation for buildings - Google Patents

Abstract

Foundation for a building, which includes at least one anchored in or on the ground, consisting of a substantially concentric inner and outer tube tubular component (Duopile), characterized in that the inner and outer tubes are pushed together with a substantially circumferential gap, wherein the gap is at least partially filled with at least one pourable and / or flowable filling material.

Description

Wind turbines (WEA) have in recent years by a rapid technical Development dimensions and weights reached, increasing the limit of the technologically feasible. Rotor diameter well over 100m, tower heights of up to 130m u. Tower head masses of 500 tons belong today to the state of the art.

Especially Tower and foundation are components in which the component size increasingly problematic becomes. For the road transport of the predominantly used tubular steel towers represents a diameter of 4.3m usually a border (bridge height), continue to limit the to disposal standing rolling mills and welding processes the Wall thickness and also the diameter of the workable, rolled steel sheets. Additionally limited also the permissible one Transport weight of currently about 100t piece weight the dimensions. Higher unit weights to lead at a considerably higher cost.

increasing Interest in wind energy gains offshore use, d. H. Wind turbines are placed in the sea (comparable to oil rigs). Because of the much higher Installation u. Maintenance costs is the offshore use of wind energy under a very strong cost pressure. The founding of the machines on the Seabed represents a significant cost factor. As especially economical for mean water depths has so far been the so-called monopile (one-pile) founding The isolated also for land-based Wind turbines is already being used. Here is a in the renewal the tower axis befindlicher pile, usually a relatively thick-walled Steel tube, anchored in the (sea) floor. This single stake has to at big Wind turbines have considerable dimensions, for example Diameter of over 5 meters at lengths from above 30 meters. It is already foreseeable that in the near future components not in the required size are more manufacturable.

The Most economical methods for introducing the pipe into the ground is the piling method. In sandy soils, the rinsing process is also known. On rocky surfaces Furthermore, the drilling method is known in which then the monopile depends on the soil texture optionally with a concrete-like mass (grout) cemented into the wellbore.

A similar cemented connection is known at the offshore wind turbines for the transition monopile tower. Since the top of the monopile is uneven, in particular during the ramming process, are otherwise usual Flange connections not possible. Therefore, a transition pipe, which is provided at the upper end with a flange over the Monopile put over. This transition pipe usually has much excess to monopile, so that an angle error occurred when inserting the monopile can be compensated. After alignment of the transition piece, the gap between transition piece and monopile then filled with a concrete-like mass (grout). The filling material is not used here just to fill of the cavity, but as a bonding material (physical adhesion) between the components. This connection, called "concrete bonding" is commonly known as grouted joint.

Especially in the very economic pile driving the dimensions of Monopiles in both diameter and wall thicknesses the available standing rams, of course considerable dimensions have to have limited. Furthermore Can a high weight of monopile at unacceptably high cost during handling and transport.

on the other hand It is due to the enormous static and dynamic loads during the 20th Lifetime of a WEA is generally desirable from a constructive point of view, one possible to realize stable and stiff structure. In addition, often the first natural frequency of the structure kept in a permissible frequency window which are predetermined by the structural design of the other wind turbines is. Especially with larger water depths The frequency requirement can thus lead to a monopile with available standing border dimensions can not be realized.

at greater water depths belong therefore three-star establishments (Tripods) and so-called jackets (four-legged or multi-legged, mostly designed as a truss structure Platforms, common execution at the oil platforms) to the known foundation possibilities for wind turbines. The Anchoring the "feet" may be accomplished via, for example, gravity (Concrete) as well as by anchored in the ground piles. Due to the considerably higher Steel consumption and the large number of associated with considerable effort Anchoring points on the seabed are these foundations however far less economical than the monopile. Continues the spatial Expansion below the water surface increases the risk of ship collisions represents.

Pile-shaped foundation elements are also generally known for the foundation of any kind of buildings in resilient substrates. Prefabricated piles made of reinforced concrete are usual for this purpose. Are known continue, for example from the DE 44 39 115 Concrete multi-part piles, which are successively rammed telescopically into the ground and in which the remaining cavities are successively filled with concrete.

aim The invention is a general reduction of the dimensions and Weights of the founding of structures, in particular WEA, required foundation piles both the manufacture, as well as the transport and the introduction into the floor at all to enable or at least improve the economy. Especially is the expansion of the field of application of the very economic Monopile foundation of great Interest, what must succeed, with the available permissible Dimensions of foundation piles one, the forces occurring safe transferring, very stiff and durable construction to think.

division the at a building foundation for power transmission structure required in the ground in at least two concentric Components that are manufactured individually, transported and placed in the ground and only then with one (or several different) fill or Also connecting material (ien) are connected to each other.

in the The following is with the term filler in principle also Covered with the function of connecting with, as in the embodiment of the invention, the transitions between pure backfilling and pure bonding sliding and of the same material can be covered.

With the according to claim 1 executed Embodiment of the invention founding is it thus possible at the same outer diameter the wall thickness to reduce the pile considerably, since the additional introduced Inner pile transmits additional forces as well stiffening effect. Conversely, it is also possible for a given wall thickness the outer diameter of the (outer) pile to reduce, and thus in large wind turbines the Manufacturability, transportability or incorporation into the Soil (e.g., ramming or drilling). Because of this new foundation pile practically consists of two concentric nested, tubular piles, the term "duopile" was chosen.

Out economical reasons Particularly advantageous is the execution as a monopile (Einpfahlgründung), what the extra Advantage provides that of the once positioned ram the same both piles can be driven successively concentric into the ground, or only one hole in the ground is required and both piles of a position can be introduced into the ground.

at larger structures or offshore wind turbines in deeper water sees a further advantageous embodiment of the invention, the use the known tripod foundation (Tripod) before, in the however, each leg is based on the duopile principle of the invention.

In a preferred embodiment the invention, the space between the tubes with a preferably non-polluting bulk material, e.g. Sand or gravel as filler filled, about a relative movement of the pipes under possible loads to avoid. As a bulk material transmits neither tensile nor shear load, serves the filling material in this case exclusively to the filling the interspace and thus for fixing the tubes together, but not for the additional increase in stiffness of the foundation pile. Advantage of this design is the particular in the offshore application very easy disassembly of the structure after the end of its life, after the removal of the founded Build the outer steel pipe in the range of height the seabed is separated and caught up, the bulk being simple is released to stay on the seabed. In a second Operation can then be separated and caught up the inner tube.

A further, particularly advantageous embodiment of the invention sees before, the filler to increase in stiffness to use the entire pile, in which it is sort of out of the fiber composite area known sandwich construction, the shear transfer between two load-bearing Ensures material layers. Such a construction can be achieved in which as a filler a e.g. high-strength concrete (grout) known from offshore technology is used.

Around a good connection of the filling material with To ensure the steel components, as well as the transmission of shear stress from the steel pipes into the filler to enable can special measures be required. An embodiment The invention provides annular material accumulations on the inside of the outer tube as well as the outside form the inner tube (so-called shear keys). This can e.g. by welding of steel bands or especially economically only by build-up welding.

A particularly advantageous embodiment of the invention provides, in order to improve the connection filler / pipe on the outside of the inner tube in the longitudinal direction extending ridges apply. Complementarily, webs are also applied in the longitudinal direction on the inside of the outer tube, which are directed inwards. The Arrangement of the webs is expediently chosen so that alternate in the mounted state along the circumference always webs from the inner tube and the outer tube.

These Arrangement still has the distinct advantage that at least Three of the bars can be used to the two tubes during the Centering assembly process in each other, in which the height of the webs on the inner or outer diameter of the associated second tube is tuned.

to Further improvement of the connection filling material / pipe can make sense be in the rib-shaped Components recesses (holes) provided. This measure also provides an even distribution of the filling material while of the filling process for sure.

at especially hard floors It can happen that the longitudinal webs would not withstand the stresses of the piling process. In In this case, another embodiment of the invention provides using at least three spacers a fastener (rope, rod or the like) from above into the space contribute. The spacers can e.g. be made of plastic, metallic material, or even wood. Depending on the length It may be necessary to use spacers at different positions on the longitudinal direction the piles) contribute.

Of the Connection of the foundation pile to the rest of the building is preferably carried out with the in itself Known in the art concrete grouting (grouted joint). A special advantageous embodiment The invention provides that the diameter of a substantially tubular transition piece is chosen so that it is in the space between inner u. outer tube can be pushed. After alignment of the transition piece this can then by means of the concrete bonding (grouted joint) with the interior u. the outer tube preferably be connected in one operation.

Preferably is the transition piece as well with the above explained Means for increasing the shear transfer between transition piece and filler fitted.

alternative can the transition to the rest of the building also over in the prior art conventional compounds, e.g. Flange or tab connections, etc. take place.

All mentioned components of the invention are particular, but not exclusively for offshore structures of high economic benefit.

component the invention is not only the execution of the duopile according to the invention, but especially the method of constructing such Foundation pile.

For this it is intended, either in a first step either first the outer tube or first bring the inner tube into the ground. In a second step then the tube complementary to the first step is introduced. Optional can already do a complete or partial backfilling of the intermediate space. In a next step will be then mounted the transition piece, which in principle can be pushed into the inner tube, technically far more meaningful but outside about that outer tube or even more advantageously between the exterior u. pushed the inner tube becomes. In a further step, the (the) Column) between duopile tube (s) and transition piece filled with a filling material. at the preferred embodiment, at the transition pipe into the space between outer u. Inner tube is pushed, the filling of the two column can be common or also successively (in two steps). Also can it makes sense to use the filler material start in the gap to the inner tube in a slightly different area and end up in the gap to the outer tube. Reduced in this way one the stiffness jump at the transition from the duopile to the transition piece.

at a preferred embodiment of the invention includes the method in addition to filling the (the) column) to. Transition piece too at least partial filling the gap between interior u. Outer tube with a filling material or with different filling materials. This filling finds most appropriate but not necessarily between step two and three of the method described above.

The permanent sealing of the gap between foundation pile and transition piece is preferably carried out with a permanently elastic material in a final step.

The economic introduction of the duopile foundation is preferably carried out with the ramming method, as far as the soil conditions allow. Other Methods (e.g., drilling) are also applicable.

The method according to the invention is particularly useful for offshore structures, since there the logistical requirements, in particular also with regard to the machines required for introducing the piles into the ground, are economically viable meet.

component The invention also relates to a method for disassembling a inventive foundation, which is particularly advantageous if the gap between Interior u. Outer pile essentially with a pourable, preferably not environmentally hazardous filling material filled has been.

After this the structure and preferably also the transition piece were dismantled, takes place Disassembly of the foundation. In a first step, the outer pile of the duopile will be in the first step Range of height of the seabed, e.g. with known underwater suitable Cutting practices. Dependent from the requirements of the official Building permit may be slightly below the level of the seabed mean the seabed (so that first excavation work or free rinses to be carried out) or even up to a few meters above the seabed, where the separation with the available devices is easiest to perform.

In In a second step, the outer tube is caught up, so that the filling material goes down to the seabed. Especially with a sand- or gravel-like, non-polluting filler can this on remain the seabed. In a third step, then (possibly after renewed excavation work or rinsing work) the inner tube in Range of height of Seabed separated and caught up.

There the foundation according to the invention in particular Use particularly advantageous in the field of wind energy utilization is, a wind turbine with inventive foundation is expressly part of the present invention.

Below is in the 1 - 2 the invention further explained.

1 shows two preferred embodiments of the invention foundation

2 shows a section through a further preferred embodiment.

1 represents an application of the invention as founding an offshore wind turbine.

shown are left and right of the vertical dash-dotted symmetry line two different embodiments of the invention, in reality are normally designed rotationally symmetrical. At WEA with strong Main wind or main shaft direction but it may also be useful for economic reasons above the Scope of the pile to use different fillers (e.g., low load gravel and high quality gravel) filling material (e.g., grout) in the main load direction).

With ( 1 ) respectively. ( 2 ) are the inner and the outer tube called, which were introduced into the seabed.

In the space between ( 1 u. ( 2 ), the transition piece ( 3 ), which at the upper end with a conventional screw flange as a connection to the further structure ( 8th ) is provided. In the right-hand variant 1 only the area of concrete bonding to the transition piece with the filling material ( 6 ), which is why at the lower end of the transitional part ( 3 ) seals on both sides ( 4 ) to the interior u. Outer tube are attached. Such seals are state of the art in grout joints. They are shown directly next to each other, lying on the same building height. In order to avoid a structurally unfavorable strong jump in stiffness in the structure, it may be useful to arrange one of the two seals, eg the inner one, a little further down, so that the transition is less abrupt. The same applies to the upper level of backfilling. Again, it may be useful for the reasons mentioned, for. B. to fill the inner gap less high than the outer.

During the assembly process, the support and orientation of the transition piece ( 3 ) on the inner tube ( 1 ) using support brackets ( 5 ). In principle, the support brackets ( 5 ) also outside on the outer tube ( 2 ), for corrosion protection reasons, the attachment on the inside, however, makes more sense. After introduction of the filling material, the remaining gap between transition piece ( 3 ) and outer tube ( 2 ) meaningful way with a permanently elastic mass ( 7 ) sealed.

variant 2 (left side) shows the on both the inner and outer tube ( 1 u. ( 2 ) as well as on the transition piece ( 3 ), in this example ring-shaped ( 9 ) for improving the connection between filling material ( 6 ) and pipes ( 1 ) 2 u. ( 3 ).

If by means for increasing the thrust transmission, a simple version of the variant 1 illustrated seals ( 4 ) is not possible, the space between the tubes ( 1 u. ( 2 ) to slightly below the end of the transition piece with inexpensive, preferably not environmentally hazardous filling material ( 10 ) (eg sand or gravel) are filled in (the right of the two alternatives shown) 2 ). Then only the introduction of high-quality (and relatively kostspieli conditions) filling material for concrete bonding (grout). Furthermore shown in the variant 2 a different filling level of the upper level of concrete filling to avoid the above-described strong stiffness jumps.

Depending on the requirements of the location of the building but it is also alternative as described above, the filling material as a load-bearing part of the entire foundation pile (depending on Einbringungsart to the level of the seabed or even to the lower end of the Duopile) execute. In this case, the bottom cheap filling material ( 10 ), and filled the entire space with the high quality filler.

In an even more advantageous because more economical embodiment But the invention can also be the high quality filler only locally there, where the stress level is particularly high (e.g., directly above the Clamping on the seabed or in the transition area to the transition piece, or also different depending from the main loading direction).

2 shows a further embodiment of the invention. Shown is a sectional view of the inner tube ( 1 ) and the outer tube ( 2 ). For better connection of the filling material to the tubes, both inner tube ( 1 ) as well as outer tube ( 2 ) with bars ( 11 ) Mistake. Three of the webs fixed to the inner tube are dimensioned in height so that they ensure the centering of the tubes during the introduction into the ground ( 12 ). To improve the connection to the filling material, the webs may be provided with recesses. At the bottom, they can be chamfered to facilitate insertion into the ground.

Claims (22)

Foundation for a building, which includes at least one anchored in or on the ground, consisting of a substantially concentric inner and outer tube tubular component (Duopile), characterized in that inner u. Outer tube are pushed into one another with a substantially circumferential gap, wherein the intermediate space is at least partially filled with at least one pourable and / or flowable filling material. founding according to the preceding claim, characterized in that the foundation of a single, essentially in the extension of the building's high axis running duopile executed is. founding according to claim 1, characterized in that the foundation as Tripod (tripod) running is, where each leg is founded as a duopile. founding according to one of the preceding claims, characterized that it is the filler material at least partially to a preferably not environmentally hazardous bulk (e.g., sand or gravel). founding according to one of the preceding claims, characterized that it is the filler material is a concrete-like mass (grout). founding according to one of the preceding claims, characterized that the outer tube on the inside as well as the inner tube on the outside with means to increase the shear transmission between pipe and filling material are equipped. founding according to the preceding claim, characterized in that the means to increase the shear transfer in the form of a ring realized on the pipes material accumulations are realized. founding according to claim 6, characterized in that the means for increasing the shear transfer from at least three parallel to the longitudinal axis of the Duopile oriented, and with one of the pipes connected components (webs) exist. founding according to the preceding claim, characterized in that at least three of the webs ensure the centering of the inner and outer tubes. founding according to one of the preceding claims, characterized that for centering the tubes during the Einbringvorgangs at least three spacers via connecting means permanently or temporarily be introduced from above into the space. founding according to one of the preceding claims, characterized that the connection from the duopile to the further structure by a preferably tubular transition piece takes place, which at the upper end preferably via a screw flange connected to the building and at the bottom over a Concrete bonding (groutet joint) is connected to the Duopile. founding according to the preceding claim, characterized in that the transition piece in the Gap between interior u. Outside tube is pushed. founding according to claim 11 or 12, characterized in that the transition piece with means to increase the shear transmission between transition piece and filler Is provided. founding according to one of the preceding claims, characterized that the building is an offshore structure. Method for introducing a, from a substantially concentric interior and outer tube existing, tubular Component (duopile) in the ground to establish a structure, preferably a WEA, with interior u. outer tube pushed together with a substantially circumferential gap and the connection between the duopile and the building realized by a transition piece is, with the transition piece with a filling compound is associated with the Duopile, characterized in that - in one first step the foreign or the inner tube is introduced into the ground - in one second step, the inner tube in the outer tube or the outer tube over the Inner tube pushed and introduced into the ground - in one third step, a transitional over, between or pushed into the duopile - and in a fourth step the gap (s) between duopile and transition piece at least partially with a filling material filled becomes. Method according to the preceding claim, characterized that in an additional step, preferably between step two and three, the gap between Interior u. outer tube at least partially filled with at least one filler. Method according to one of the preceding claims, characterized characterized in that in an additional last step the transition between duopile and transition piece with one preferably permanently elastic mass is sealed. Method according to one of the preceding claims, characterized characterized in that the introduction of the tubes by the piling method and / or drilling. Method according to one of the preceding claims, characterized characterized in that it is an offshore structure and the piles be introduced into the seabed. Method for dismantling a building foundation with a pourable filling material according to the preceding claim, characterized in that after removal of the founded building - in a first step of the outer pile in the range of height the seabed is separated - in a second step the outer pile is caught up with the filling material is released down to the seabed - in one third step of the inner pile in the area at the level of the seabed separated and subsequently caught up. Method according to the preceding claim, characterized that the transition piece between founding and building only in an intermediate step between step one u. Step two is dismantled. Wind turbine with a foundation according to one of the preceding Claims.