EP0185268A2 - Accessible bottom construction for a refuse dump - Google Patents

Abstract

A basemented floor structure under a waste dump, whereby the burden of the waste body is transferred to piers and then onto foundations and the subgrade, and on which layers of sealing material, drainage material or protective material lie, is built up from individual support elements separated from one another by seams and having an upwardly convex or concave shape. By this structure, unequal setting of the subgrade can be accommodated without harm and cracks in the floor structure are prevented. The upper surfaces of the support element are inclined toward the piers. The seepage is taken from collecting zones through a water removal system to a purification plant.

Description

The invention relates to a walk-through sole construction for a landfill with which the load of the landfill body is released on supports and further on foundations and the subsurface and on which layers of sealing material, drainage material or protective material lie, which are connected to a drainage system for the leachate.

It has recently been proposed to prevent possible contamination of the soil and groundwater under landfills by creating a cellar-like cavity below the landfill.

With such a basement landfill, the aim is to reliably collect and collect all sikker water, to be able to easily check the reliability of the sealing system at any time and to quickly identify and remedy damaged areas. Another aim is to be able to collect leakage water or leachate in the event of damage using a second system.

Sealing with a cellar-like cavity is many times more expensive and complex than previously used seals, but it has the advantage of being able to visually check and secure the seals at any time in a simple manner.

In a known embodiment, the landfill body rests on a concrete slab that has a basement. The basement is accessible. The concrete construction can be done in in-situ concrete or precast construction. The main sealing function is performed by a suspended plastic seal (similar to a suspended ceiling) that clings as closely as possible to the basement ceiling and has elastic properties.

The platform top is divided into individual fields by raised field boundaries. The leachate is recorded field by field and analyzed for its nature.

These known proposals do not take into account the large deformations to which such a construction is exposed under the loads from the landfill body onto a surface that is always more or less compressible. The consequences of these deformations are additional stresses and possibly also cracks in the construction, which can destroy the intended purpose. In view of these cracks, which are considered inevitable, the suspended waterproof ceiling is therefore arranged below the actual concrete ceiling and the seepage water that penetrates through the cracks and joints in the structure is collected and drained off with this ceiling.

The problem of sealing cannot be solved with this, since the leachate contaminated with various pollutants would, starting from the cracks, attack the supporting structure itself and possibly destroy it.

Another danger, which was not recognized in the known sole construction and was not taken into account accordingly, arises from the large horizontal forces which can act on the construction in the event of an earthquake, for example.

The present invention is based on the object to improve a walkable, controllable and repairable sole construction under a landfill so that it for a long time rooms is highly resilient and tight in the long term and can also adapt to the deformations of the surface without damage.

According to the invention, the object is achieved in that the sole construction consists of individual support elements separated by joints with an upwardly convex or concave shape, the surface of which is inclined towards the supports which rest on supports arranged in a grid and which at the same time collect zones for the leachate form, which are connected to the cleaning system via the drainage system.

The individual support elements, separated from each other by joints, transfer their loads to the supports arranged in a grid, which are based on the existing floor conditions, for example on simple block foundations. The shape of the support elements ensures that the leachate flows, without crossing a joint, over a short distance to the associated collecting zone, from where it is drained into corresponding drain lines to the cleaning system. The drainage system can be present several times in order to separate the seepage water from different zones according to its pollutant content and treat it separately. The leachate flowing out of the collecting zones can first run through a sight glass for visual control, which is equipped with a device for measuring the amount of leachate and a drain tap for taking samples. The leachate then flows through a flexible, reversible hose into a drain line of the corresponding leachate category.

The support elements can be designed in detail according to claims 2 to 5. Cross vaults or folding structures are equivalent components.

Preferably, the upwardly convex supporting elements are designed as three-axis cross vaults or arch-like folding structures which are statically fixed on three supports, so that they can follow an uneven setting of their supports without constraint stresses. For the same reason, support elements that are concave upward are preferably given only one central support.

Each support has two tasks to fulfill, according to claim 6, namely that it must on the one hand pass the bearing forces of the support elements onto the foundations and on the other hand it forms the collecting zone for the seepage water flowing off on the back of the support elements. The cavity in the hollow supports and immediately above the supporting elements is filled with a well-permeable material (sand, gravel, etc.) and well compressed. The shape of the vaults or the folding structures is designed in accordance with the support line, so that they are essentially only subjected to pressure and any bending stresses that may occur remain small.

Since the horizontal stresses in the vault cover are always smaller than the associated vertical stresses from the dump, the support line is a standing half-ellipse.

In order to prevent a risk of the sole construction being destroyed by leachate containing pollutants, the surfaces of the supporting elements which are exposed to the leachate and the cavities are treated in accordance with claim 7.

According to claim 8, the support elements have closable openings through which lances which can be pushed up into the landfill body can be inserted. With the aid of these lances, measurements of parameters of the chemical, physical or biological processes taking place there can be carried out and substances can be added or extracted in the landfill body.

Depending on the deformability of the selected supporting elements or the building material of these elements and the expected change in shape of the building ground, the joints between the individual supporting elements according to claims 4 to 12 remain movable for the entire life of the sole structure or are closed or they decay as the movements subside can be designed to be closed from the start if the shape-changing capacity of the construction allows for this with regard to the expected shape changes of the subsurface and the load-bearing capacity and tightness of the construction remain guaranteed.

Movable joints are only guided along a fall line so that no seepage water flows towards them, but only runs parallel to the joint. The capstone lying over the joint has the task of bridging the open joint and the loads in this area on the two neighboring supports transfer elements. Between the outer sealing system facing the landfill body (primary system) and the inner sealing system (secondary seal), which is arranged towards the inside, there is a freely drainable space from which any seepage water that has entered can flow out in a controlled manner. In the event of a leak in the outer sealing system, the seeping water entering this space can be detected and discharged harmlessly. This space can also be squeezed out watertight with a suitable mass, this mass being such that it can be removed from the inside and can be replaced with a new one at any time and as often as required.

According to claim 14, it is advantageous if a further sealing layer inclined above the collecting zones for the leachate with an overlying drainage layer is arranged above the supporting elements and the layer of protective material as well as the layer of drainage material above it, which has downpipes with the collecting zones and the drainage system for the leachate are connected.

With this upstream sealing layer, the majority of the leachate can be fed to the collecting zones in the same way via the downpipes without the leachate touching the surfaces of the support elements. Only a small amount of leachate, which penetrates the sealing layer, flows over the surfaces of the support elements. As a result, the stress on the sealing layer on the surface of the support elements is reduced and, at the same time, their service life is extended.

Embodiments of the invention are explained below with reference to the drawing.

• Fig. 1 einen Schnitt entlang der Linie F/1 der Fig. 2,
• Fig. 2 eine schematische Draufsicht auf eine Sohlenkonstruktion gemäß Fig. 1,
• Fig. 3 ein erstes Ausführungsbeispiel eines Tragelementes,
• Fig. 4 eine axionometrische Teilansicht einer Sohlenkonstruktion mit Tragelementen gemäß Fig. 3,
• Fig. 5 eine schematische Draufsicht auf eine Sohlenkonstruktion mit viereckigen Tragelementen,
• Fig. 6 eine schematische Draufsicht auf eine Sohlenkonstruktion mit sechseckigen Tragelementen,
• Fig. 7 eine schematischeDraufsichtauf eine Sohlenkonstruktion mit trichterartigen sechsseitigen Tragelementen,
• Fig. 8 eine axionometrische Ansicht mit vierseitigen trichterartigen Tragelementen,
• Fig. 9 eine schematische Draufsicht auf eine Sohlenkonstruktion mit trichterartigen vierseitigen Tragelementen,
• Fig. 10 der Schnitt durch eine bewegliche Fuge und
• Fig. 11 einen Schnitt durch eine andere Ausbildungsform einer beweglichen Fuge.

It shows:

• 1 shows a section along the line F / 1 of FIG. 2,
• 2 shows a schematic top view of a sole construction according to FIG. 1,
• 3 shows a first embodiment of a support element,
• 4 is a partial axionometric view of a sole construction with support elements according to FIG. 3,
• 5 is a schematic plan view of a sole construction with square support elements,
• 6 is a schematic top view of a sole construction with hexagonal support elements,
• Fig. 7 is a schematic plan view of a sole construction with funnel-like six-sided support elements,
• 8 is an axionometric view with four-sided funnel-like support elements,
• 9 is a schematic plan view of a sole construction with funnel-like four-sided support elements,
• Fig. 10 shows the section through a movable joint and
• Fig. 11 shows a section through another embodiment of a movable joint.

1 and 2 show a sole construction 1 with triangular cross vaults 18 via supports 20 or hollow supports 45 arranged in a triangular grid.

3 shows a triangular cross vault in a single axionometric view, whereas FIG. 4 shows an axionometric view of a section through the sole construction 1 with three-axis cross vaults 18 and a landfill body 2 arranged above it. In the following description of the first embodiment, reference is made to FIGS. 1 to 4.

First, however, it is pointed out that the triangular cross vault 18 according to FIG. 3 is only one possible embodiment in embodiment 1 of the invention. Instead of the three-axis cross vault 18, a three-sided folding mechanism can also be used. Any person skilled in the art is able to replace cross vaults with appropriate folding mechanisms within the scope of the present invention.

Below the three-axis cross vault 18 is a walk-in basement 3, from which the joints, which will be explained in detail below, and the components of the drainage system can be checked and repaired.

A three-axis cross vault 18 consists of three firmly connected vault parts with an outwardly facing surface 43. The upper Surface 43 of the three-axis cross vault 18 is designed in such a way that the leachate runs along water flow arrows 42.

The individual supporting elements or three-axis cross vaults 18 are separated from one another by joints 51, 52 and 53, which are explained in more detail below.

Each three-axis cross vault 18 rests on three supports 19. Here, the supports 19 rest on supports 20 and 45, respectively. If three-axis cross vaults 18 or corresponding folding mechanisms are used for the sole construction 1, the supports 19 rest on the corresponding edge regions of supports 20 or hollow supports 45, as shown in FIGS. 1 and 4. The supports 20 and 45, as can be seen above all from FIG. 4, have hexagonal edge regions 21 for the supports 19. 1, 2, 3 and 4 it can be seen that the entire sole construction 1 of the waste landfill is made up of individual support elements 18 which are separated by joints and which are convex at the top. This results in collecting zones 44 for the leachate which are distributed over the sole construction and which, as can be seen in FIG. 1, are connected directly to a lockable drain pipe 10 via a cavity 46 of the hollow support 45 or, in the case of solid supports 20. This opens out through a sight glass 11 into a pluggable hose 12 which can be connected to one of the drain lines 13. An opening for taking leachate water samples can also be connected to the sight glass 11. The changeable hose 12 is connected on the basis of the sample taken to the drain line 13 which is intended for the respective leachate.

1 and 4 show that on the sole construction 1, the surface 43 of which is covered with a layer of protective material 9, there is a layer 8 of drainage material which is closed by a separating layer 7. The actual landfill body 2 is located above this separating layer 7.

On the left side of FIG. 1 and in FIG. 4 it can also be seen that a sealing layer 63 with an overlying drainage layer 64 can be arranged above the layer 8 of drainage material. In preferred execution For example, the landfill body 2 lies on the drainage layer 64. The sealing layer 63 and the drainage layer 64 are inclined. Downpipes 65 are arranged at the lowest point and lead to the lowest point of the collecting zone 44 or the hollow supports 45.

According to the invention, the leachate is thus drained off in two ways: firstly via the downpipes 65 and secondly along the water flow arrows 42 over the surfaces 43 of the three-axis cross vault 18. It is essential that the majority of the leachate occurring is already on the surface of the sealing layer 63 via the Downpipes 65 is derived and thereby the aggressive leachate from the surfaces 43 of the three-axis cross vault 18 as far as possible. It can be seen from the figures that the water flow arrows 42 never cross one of the joints 51, 60, 61. This special feature of the sole construction 1 contributes significantly to its tightness.

The load from the landfill body 2 is transferred via the three-axis cross vaults 18 and the supports 20 and 45 into foundations, in the exemplary embodiment shown block foundations 4, which derive the load into the subsurface 5. Fills of non-cohesive material 6 are provided between the block foundations 4. It is hereby achieved that although the weight of the landfill body 2 can cause strains due to the settlement depression, these stretches cannot then be reversed.

1 and 4 also show closable openings 48 through which lances 49 can be pushed up into the landfill body 2 from below. In the exemplary embodiment shown, the lances 49 are connected to gas lines 50. Part of the lances 49 can also be used to measure 2 state variables in the landfill body, e.g. To carry out temperature, oxygen content etc. or to supply these substances and to control the physical, chemical or biological decomposition processes taking place in the landfill body 2 or to control them in a desired direction.

It is important that the sealing layer 63 can be made of material that is inexpensive compared to the layer of protective material 9. This layer intercepts most of the leachate and the downpipes 65 fed. As a result, the expensive layer 9 of protective material can be protected and its service life can be increased.

In the event that the condition of the subsoil 5 does not allow simple block foundations 4, other types of foundation, e.g. Pile foundations or the like be carried out.

In the case of a very inhomogeneous and resilient subsoil, there could be the risk that the support foundations shift against one another when the sole construction 1 is partially loaded, thereby causing constraining stresses in the supporting elements. Since the settlement trough forming under the landfill must lead to a slight increase in the column spacing and this movement must not be hindered, as already mentioned, the spaces between the block foundations 4 are filled with non-cohesive material 6, e.g. Rolled gravel filled, which sags automatically when the foundation blocks drift apart and prevents the foundations from being pushed together at the same or a different location. The sole construction 1 according to the invention can therefore only stretch, as it must do so in order to be able to follow the settlements. According to the invention, however, the sole construction is prevented from expanding more than necessary at one point and contracting at another point to compensate for it.

The supporting elements in general, including the three-axis cross vault 18 and the supports 20 and 45, can be made from different building materials and according to different building methods. As building materials come into consideration reinforced concrete, steel fiber concrete, cast steel, steel GVK "glass fiber reinforced plastic o and similar pressure-resistant and as resistant as possible to the polluted seepage waters. With the concrete construction, both prefabricated parts and in-situ concrete are possible Dimensions are easily transported and are then screwed together on site to form larger units or welded to one another Fig. 4 reveals capstones 62 over the joints explained in detail below, which in preferred exemplary embodiments are arranged over the joint area to be protected.

5, 6, 7 and 8 show schematically further exemplary embodiments of the invention.

5 shows a top view of a sole construction 1 with four-axis cross vaults 23. These have supports 24 which rest on square edge regions 26 of supports 25. If the collecting zones for the leachate are connected directly to the drainage system 10, 11, 12, 13, the supports 25 can be designed as full supports. But they can also be designed as hollow supports.

6 shows the schematic plan view of six-axis cross vaults from which a sole construction 1 can be constructed with the interposition of joints 51, 60, 61. The six-axis cross vaults 28 have supports 29 which can rest on hexagonal edge regions 31 of supports 30.

Sole structures 1, which are constructed in accordance with the schematic drawings in FIGS. 5 and 6, moreover have all the features which have been explained in connection with FIGS. 1 to 4. 5 and 6, the water runs along the water flow arrows 42 without crossing a joint.

9 schematically shows a top view of a sole construction 1 made of four-sided funnel-like support elements 33. They have supports 34 which rest on square edge regions 36 of central supports 35. The supports 35 can be designed as hollow supports or as solid supports if the collecting zones 44 are connected directly to the drainage system.

7 shows the schematic plan view of a sole construction 1 with hexagonal funnel-like support elements 38. The supports 39 rest on hexagonal edge areas of supports 40, which can be designed either as hollow supports or as solid supports.

FIG. 8 shows an embodiment of a sole construction 1 consisting of individual four-sided funnel-like support elements 33 placed next to one another, which are supported by a single, centrally arranged support 35. The supports 34 of the four-sided funnel-like support elements 33 rest on square edge regions 36 of the supports 35. The upper sides of the support elements 33 are concave at the top, so that the leachate initially flows into the collecting zone 44 for the leachate within the funnel-like support element 33 and from there through the hollow support 45 Get support 35. They then flow into the cleaning system as already described with reference to FIGS. 1 and ₄ . With larger dimensions of the support elements 33, instead of a single centrally arranged support 35, a support group of several supports can be designed and the collecting zone 44 can be connected directly to the drainage system.

Movable joints between the individual support elements 18, 23, 28, 33 and 38 essentially prevent the formation of cracks in the sole structure 1 due to settlement differences of the individual supports 20, 45 in the case of an unfavorable subsurface 5. In such cases, the movable joints 51 remain permanent or until movable for subsidence subsidence.

Once this has been done, the originally movable joints can then be closed. In this case, there is a joint 60 that can be moved for a limited time. After completion of the settlement, it can be finally closed, for example by pressing, screwing or welding - depending on the building materials of the supporting elements.

Persistent, i.e. Joints 61 which have already been closed from the start can be implemented if the changes in shape of the sole construction 1 are only very small as a result of the settlement and can therefore be absorbed by the material of the supporting elements without the risk of cracking.

10 shows a section through a continuously movable joint 51. The cover block 62, which is U-shaped in cross section, covers the region of the joint 51 and lies with its two support surfaces on the mutually facing edges of the support elements 18, 23, 28, 33 and 38 . The resulting joint 47 simultaneously forms the outer sealing system 51.

The inner sealing system 53 consists essentially of an elastically deformable seal 55 which is stretched between opposing wedge-shaped grooves 57 in the edges of the support elements 18, 23, 28, 33, 38. For this purpose, a clamping plate 56 is provided, which is fastened by means of screws in the manner shown in FIG. 10 between the opposite edges of the support elements.

Below the cover stone 62 there is a freely drainable space 54, which can also be filled with a waterproof mass 48.

A drain hose 59 is used to drain the leachate from this area of the outer seal.

The waterproof material 48 can be made of PUR foam, for example, and if necessary removed or replaced at any later time and as often as desired with a new filling. If seepage water penetrates through the joints 4 _r between the cover brick 62 and the edge areas of the supporting elements, this seepage water that has penetrated is discharged in a controlled manner through the drain hose 29 and fed to the drainage system 10, 11, 12, 13.

11 shows a further two-part sealing system for a permanently movable joint 51. The cover stone 62 lies on an outer sealing system 52, which consists of drain mats 66 resting on the supporting elements 18, 23, 28, 33, 38 and neoprene extending along the joint 51 -Profiles 67 exists. The freely drainable space 54 is closed off by an inner sealing system 53 with an elastically deformable seal 54 towards the walkable sole construction 1. The inner seal system 53 can be easily removed for inspection and repair of the outer seal system 52. The areas of the drainage mats 66 pointing towards the joint 51 are pressed with concrete, for example. If necessary, this pressing process can be repeated using the pressing tubes.

List of terms used

• 1. Sole construction
• 2. Landfill body
• 3rd basement
• 4. Block foundation
• 5. Underground
• 6. Non-cohesive material
• 7. Interface layer
• 8. Layer of drainage material
• 9. Single or multi-layer seal made of protective material
• 10. lockable drain pipe
• 11. Sight glass
• 12. reversible hose
• 13. Drain pipe
• 14.
• 15.
• 16.
• 17th
• 18. triaxial cross vault
• 19. Support
• 20. Support
• 21. hexagonal border area
• 22.
• 23. four-axis cross vault
• 24. Support
• 25. Support
• 26. square edge area
• 27th
• 28. six-axis cross vault
• 29th support
• 30. Support
• 31. hexagonal border area
• 32.
• 33. four-sided funnel-like construction
• 34th support
• 35. Support
• 36. square border area
• 37.
• 38. six-sided funnel-like structural part
• 39th support
• 40th support
• 41. hexagonal border area
• 42. Water flow arrow
• 43. surface
• 44. Collection area for the leachate
• 45. Hollow support
• 46. Cavity
• ₄₇ . Joint between capstone and supporting element
• 48. closable opening
• 49. Lance
• 50th gas pipe
• 51. continuously movable joint
• 52. external sealing system
• 53. inner sealing system
• 54. free drainable space
• 55. elastically deformable seal
• 56. Clamping plate
• 57. wedge-shaped groove
• 58. waterproof mass
• 59. Drainage hose
• 60. joint that can be moved for a limited time
• 61. permanently closed joint
• 62. Capstone
• 63. sealing layer
• 64.Drain layer
• 65. Downpipe
• 66.Drain mat
• 67. Neoprene profile
• 68. Injection tube

Claims (14)

1. Walk-in sole construction for a waste landfill with which the load of the landfill body is released on supports and further on foundations and the subsurface and on which layers of sealing material, drainage material or protective material lie, which are connected to a drainage system for the leachate, characterized that the sole construction (1) consists of individual support elements (18, 23, 28, 33, 38) separated from one another by joints (51, 60, 61) with an upwardly convex or concave shape, the surface (43) of which supports (19, 24, 29, 34, 39) are inclined, which rest on supports (20, 25, 30, 35, 40) arranged in the grid and which at the same time form collecting zones (44) for the leachate, which are discharged via the drainage system ( 10, 11, 12, 13) are connected to the cleaning system. 2. Sole construction according to claim 1, characterized in that the supporting elements are triaxial, upwardly convex cross vaults or folding mechanisms (18), the supports (19) of which rest on hexagonal edge regions (21) of the supports (20). 3. Sole construction according to claim 1, characterized in that the supporting elements are four-axis, upwardly convex cross vaults or folds (23) whose supports (24) rest on square edge regions (26) of the supports (25). 4. Sole construction according to claim 1, characterized in that the supporting elements are six-axis upward convex cross vaults or folds (28) whose supports (29) rest on hexagonal edge regions (31) of the supports (30). 5. Sole construction according to claim 1, characterized in that the support elements are three-sided, four-sided or six-sided, upwardly concave funnel-like construction parts (33, 38), the supports (34, 39) on correspondingly shaped edge regions (36, 41) of the supports ( 35, 40). 6. Sole construction according to claims 1-5, characterized in that each support (20, 25, 30, 35, 40) is a hollow support open at the top and closed at the bottom (45), on the upper edge region (21, 26, 31, 36, 41) the supports (19, 24, 29, 34, 39) of adjacent support elements (18, 23, 28, 33, 38) rest, and their cavities (46), which are designed as collecting zones for the leachate, are connected to the drainage system (43 , 44; 10, 11, 12) and the drain line (13) are connected. 7. Sole construction according to claims 1-6, characterized in that the inclined surface (43) of the support elements (18, 23, 28, 33, 38) and the cavities (46) of the hollow supports (45) with a resistant to seepage water - or multi-layer seal (9) are made of protective material. 8. Sole construction according to claims 1-7, characterized in that in the supporting elements (18, 23, 28, 33, 36) closable openings (48) are provided for lances (49) which can be pushed up in the landfill body (2). 9. Sole construction according to claims 1-8, characterized in that the joints are designed as permanently movable joints (5). 10. Sole construction according to claims 1-8, characterized in that the joints are designed as temporary movable joints (60). 11. Sole construction according to claims 1-8, characterized in that the joints are designed as permanently closed joints (61). 12. Sole construction according to claims 1-10, characterized in that over the joints (51, 60, 61) cover stones (62) are arranged which bridge the immediate joint area. 13. Sole construction according to claim 9 u. 10, characterized in that each movable joint (51) contains a single or multiple sealing system, the in the latter between the outer and inner sealing system (52, 53) a freely drainable space (54) is arranged, and that these sealing systems are observable and repairable from the freely accessible space below the support elements (18, 23, 28, 33, 38) . 14. Sole construction according to claims 1-13, characterized in that over the support elements (18, 23, 28, 33, 38) and the layer of protective material (9) and the overlying layer of drainage material (8) another, over the Collecting zones (44) for the leachate inclined sealing layer (63) with an overlying drainage layer (64) are arranged, which are connected to the collecting zones (44) and the drainage system (43, 44; 10, 11, 12, 13) via down pipes (65) and the drain line (13) for the leachate are connected.

Images