Method and device for filling and compacting a viscous building material layer by layer in a drilled hole

Abstract

The invention relates to a method for filling and compacting a cohesive building material, in particular a cohesive earth material, layer by layer in at least one borehole close to the ground, wherein the cohesive building material is introduced into the at least one borehole and compacted layer by layer using a conveying device comprising a filling tamper driven by means of a rigid chain propulsion device.

Description

Technical Field

[0001] The invention relates to a method and a device for backfilling and compacting layer by layer a cohesive building material, in particular a cohesive earth building material, in at least one borehole close to the surface and in a deeper formation, and to the cohesive building material used therefor. Background Art

[0002] For example, hundreds of thousands of near-surface drillings are performed every year in the fields of water and well construction, explosive ordnance detection, geothermal energy, point construction, landfill protection, dam repair, etc. Drilling is necessary, for example, to explore the ground for construction, to pump water, to install geothermal heating systems, to locate explosive ordnance, to identify raw materials, etc.

[0003] In the exploration of explosive ordnance, large areas are drilled which are subsequently intended for, for example, transport infrastructure. Boreholes with a diameter of 100 mm to 120 mm and a depth of 6 m to 8 m are common. Some of the drilling is performed as spot soundings (a small number of holes per suspected location), others are large-scale soundings carried out in a grid of 0.5 m to 1.7 m. A large part of the area drilled in this way will be covered by roads and railway lines after confirmation that there is no explosive ordnance. Therefore, there are special requirements for the backfilling of the boreholes.

[0004] Every drilled hole disturbs the ground. However, backfilling disturbs the ground even more than the actual drilling. Settlement, erosion, shrinkage, material shrinkage in the backfill area and thus instability of the drilled and backfilled building ground can occur.

[0005] The drilled holes must always be backfilled professionally. Legal regulations and technical practice specifications apply here, such as DVGW Regulation 120; DIN 4904:2017 Casting of sealing stones in well construction; DIN 4905:2019 Hydraulically hardened suspensions.

[0006] The technical requirements for borehole backfilling vary from industry to industry and depend on the type of further use of the borehole site.

[0007] In principle, the natural seal that has been drilled must be backfilled with a natural hydraulic barrier in order to exclude hydraulic short circuits between the possibly contaminated surface water and the pure groundwater. The natural seal usually consists of a naturally occurring clay or loam layer, also known as a groundwater dam. Regardless of the type and purpose of the drilling procedure, a groundwater dam that has been drilled must always be hydraulically sealed again.

[0008] To achieve this hydraulic seal, a filler with castable expanded clay moldings or granules is usually introduced into the borehole as a sealing element. The limitations of this type of seal are on the one hand the installation depth and on the other hand the free filling opening, such as the annular space or the borehole diameter.

[0009] Greater installation depths with simultaneously smaller gap openings are usually achieved with hydraulically hardened suspensions, primarily cement-bound building materials, which are mixed into the suspension and injected via a pump and hose inserted into the drilled hole.

[0010] In some industries or fields of application, the described procedure has not proven to be ideal. In particular, if the intention is to use the borehole area after borehole plugging for technical infrastructures where special loads (horizontal, axial, dynamic) will occur, rigid cement columns or initially loose clay fillings pose a risk to the technical infrastructure.

[0011] Particularly in the field of traffic infrastructure, for example in the area of ​​roads, motorways, railways or dams, it is required that the borehole seal be designed such that it can quickly absorb loads and act quickly in the same way as the surrounding rock of the borehole with regard to soil dynamics.

[0012] Near-surface boreholes are backfilled primarily by pouring suitable soil building materials (primarily dry-cast expanded clay) or compressed cement-bound suspensions.

[0013] Casting expandable sealing stones as described in DIN 4904:2017 is the most widely used standard method for backfilling near-surface boreholes. Backfilling is relatively inexpensive, can be carried out without special mechanical work and is ecologically sound to the greatest extent possible. However, due to the geometry and conditions of the boreholes, bridging phenomena regularly occur when pouring the expanded clay bodies, so that larger air-filled cavities form in the underground backfill. These cavities cause additional settlements not only within the fill material, but also in the ground as a whole. If these settlements lead to even the smallest deformations in the dynamically loaded transport infrastructure area, extensive subsequent damage can occur, in the process necessitating route closures and extensive route repairs.

[0014] The use of a cement-bound suspension (known in technical usage as "dammer") to compress the borehole, also known in technical usage as "plugging", produces a predominantly rigid cement column in the borehole as a sealing element. These rigid columns are suitable for use on ground surfaces, such as building ground surfaces and foundations in civil engineering, after drilling and backfilling. For example, rigid cement columns stabilize the subsoil, in addition to pile foundations. However, in the field of dynamically loaded traffic infrastructure, rigid columns are a potential threat to traffic safety. In traffic facilities, railway tracks, bridge foundation areas, highways and waterways, in drilling in a tight grid, rigid columns can lead to undesirable and dangerous vibrations, upwelling vibrations and resonances. Since resonances can be imagined under dynamic loading, damage to the track bed or segregation of the homogeneous soil structure is conceivable and must be avoided at all costs. In addition, any compression of liquid building materials will leave a so-called sedimentation funnel at the top of the ground. These settlements after liquid backfill are often so deep that the upper area of ​​50 cm to 100 cm has to be backfilled again after the suspension has hardened, which requires a lot of additional work.

[0015] A less common form of borehole filling is to stuff clay cylinders into the borehole. Expanded clay granules are dry packed into cardboard tubes, which are fitted with caps and couplings at the ends. These cylinders are pushed into the borehole one by one, and the surrounding moisture then gradually penetrates into the clay mass and expands it. This product, which originated from blasting technology, is only occasionally used in drilling technology because the borehole can only be completely filled in exceptional cases. If the cardboard cylinder is stuck in the borehole, readjustment is almost impossible and an air-filled cavity below the ground level is almost inevitable.

[0016] Backfilling of excavated material has been common for a long time, but now it has reached the limit of what is permitted. In many tenders and technical procedure specifications, "layer-by-layer compaction" is required when backfilling excavated material. This layer-by-layer compaction will restore the original undisturbed state, but there is a lack of technology to compact the soil in the borehole. The present invention is a new technology that can be used to produce the requirement of layer-by-layer compaction in the borehole.

[0017] Liquid soil filling is a conceivable form of borehole backfilling. However, liquid soil often leads to erosion damage in the borehole, which makes the soil structure unstable.

[0018] Therefore, the methods known so far have a number of disadvantages. This applies in particular to boreholes drilled in the immediate vicinity of transport infrastructure, since aerial bombs, in particular aerial bombs of the Second World War, primarily hit transport infrastructure.

[0019] First, there is a lack of uniformity in the sealing element, mainly due to the frequent bridging of the cast sealing material. This unevenness can disturb the building floor and cause settlement or slippage of traffic bodies.

[0020] Secondly, the compression mass of cement results in rigid cement columns which contribute to resonance in transportation infrastructure structures due to the accumulation of vibrations.

[0021] Thirdly, from the point of view of the construction site, it has been technically impossible or impractical to install cohesive building materials densely in a borehole so far. Layered compaction of cohesive earth materials is a common practice in all large structures, for example in landfill construction, in the construction of landfill bases, in the construction of landfill covers, in road construction, in the compaction of building floors, etc. Cohesive earth building materials are always applied in layers and then compacted on site. Cohesive earth building materials are always applied in layers and compacted in layers using construction equipment (rollers, vibrating plates, sheepshoe rollers). Layer-by-layer compaction installation in a borehole has not been possible.

[0022] Fourth, there is a lack of rapid loading capability after the backfill process.

[0023] The problem underlying the present invention is therefore to provide an improved solution for backfilling a borehole without causing disturbance of the building ground. Summary of the invention

[0024] This object is achieved by a method having the features of claim 1 .

[0025] Therefore, a method for filling and compacting a cohesive building material, in particular a cohesive soil building material or an earth building material, layer by layer in at least one borehole close to the ground surface is provided, wherein the cohesive building material is introduced into the at least one borehole and compacted layer by layer using a conveying device comprising a filling piston driven by means of a push chain drive.

[0026] The method makes it possible for the first time to mechanically compact cohesive earth building materials layer by layer in boreholes and deeper layers. In particular, this is achieved by using a specific binder or sealant as building material in combination with a conveying device or backfilling machine, the operating principle of which is based on a rigid push chain for advancing the cohesive mass, while compacting is carried out by means of plugs arranged on the push chain. Although the use of rigid push chains is known, in particular in the horizontal and vertical movement of platforms, loads such as pallets, containers, as drives for retractable windows, etc., rigid push chains have not yet been described for the drive of pistons and for driving in pipes or boreholes.

[0027] The present layer-by-layer compaction method produces a compact sealing element which is compressed by about 1 / 3 compared to the usual filling material. Within a short time, the sealing element installed in this way almost takes on the geotechnical properties (density, kf value) of the clay in the original deposit. In addition, the occurrence of cavities is reduced.

[0028] The method can be used to backfill and compact various types of boreholes. The boreholes to be backfilled can include special civil engineering boreholes or exploration boreholes such as explosive ordnance detection boreholes, construction ground exploration boreholes, boreholes for scientific purposes, geothermal boreholes, boreholes for geological exploration purposes such as in the field of seismic measurement, boreholes for construction ground, etc.

[0029] In one embodiment of the method, at least one borehole is lined with a protective tube and the viscous building material is filled into the protective tube, in particular in portions (quantities). The protective tube is thus used as a filling tube. Such a protective tube is inserted into a borehole, in particular in explosive ordnance exploration. The diameter of the protective tube is generally 40 cm to 120 cm, preferably 50 cm to 110 cm, more preferably 60 cm to 90 cm. The protective tube is preferably made of a thermoplastic material, such as polyethylene (PE) or polyvinyl chloride (PVC). The protective tube can be one piece or preferably comprises threaded sections.

[0030] In another embodiment of the method, after the first portion (or a predetermined amount) of viscous material has been introduced into the borehole, the filling piston of the conveying device pushes the viscous material to the bottom of the borehole through the protective tube and compacts the viscous material by the reciprocating movement of the filling piston in the borehole. This essentially vertical movement of the filling piston is driven by a push chain and regulated by the control technology driven by the push chain of the conveying device. Therefore, the pressure sensor measures the increasing counterpressure at the corresponding position of the piston during the movement of the piston in the borehole. Depending on the increase in pressure, there is a transition from "fast stroke" to "slow stroke = compression". The control technology realizes the filling movement of the filling piston by appropriate reciprocating motion and in this way compacts the viscous earthwork building material in the borehole.

[0031] In another embodiment of the method, during the filling of the drilled hole with the viscous building material, the protective tube is pulled out of the drilled hole stepwise, depending on the amount of viscous building material introduced. Depending on the progress of the filling, the tube serving as the filling tube is pulled out of the drilled hole mechanically; i.e. the protective tube is pulled out of the drilled hole only when the amount of viscous building material fills the drilled hole; thus, the part of the drilled hole not filled with viscous building material is supported by the protective tube. Compaction takes place outside (= below) the filling tube, i.e. at the deepest point of the drilled hole.

[0032] In another embodiment of the method, after compacting a first portion or a first amount of viscous building material in at least one borehole, the filling piston is moved out of the borehole, another second portion or a second amount of viscous building material is filled into a protective tube in the borehole, the filling piston is reinserted into the protective tube and another portion of the viscous building material is compacted by the movement of the filling piston.

[0033] This process of partially filling and compacting the viscous building material in the drilled hole is repeated until the drilled hole is completely filled and flush with the ground surface or ground level.

[0034] The portions or amounts of viscous building material introduced into the borehole by the method are preferably each the same, so that the compacted layers preferably each have the same thickness. Thus, the viscous building material can be introduced into the borehole in portions or amounts of 5 kg to 15 kg, preferably 8 kg to 12 kg (for a borehole size of 130 mm). Preferably, after compaction in the borehole, layers having a thickness of between 30 cm and 80 cm, preferably between 40 cm and 60 cm, for example 50 cm, are obtained. The number of compacted layers varies with the depth of the borehole and can be, for example, between 5 and 20 layers, preferably between 10 and 15 layers, for example 12 layers.

[0035] As already indicated above, the type of adhesive building material used is also important to this procedure.

[0036] For example, a viscous building material for filling and compacting a drilled hole includes at least one absorbent in the form of a hydrogel and a compactable soil building material.

[0037] Compactable soil building materials are understood to mean in particular those materials which can be compressed or filled to compact. Preferred soil building materials are expandable clay minerals. Furthermore, excavated soils, excavated bored material, bored material or other predominantly mineral soil types can also be used to produce the compactable building material. It is important to mix a) the water-storing hydrogel and b) the compactable soil building material.

[0038] The concept of the building material comprises two components: a) a superabsorbent-based water-storing hydrogel powder, which is mixed with water to form a water-storing gel, which serves as a basis for the absorption of b) by mixing a) and b) swellable building material particles or pellets.

[0039] In one embodiment, the present adhesive building material can be prepared from a mixture comprising: 50% to 70% by weight, preferably 60% by weight, of a swellable clay mineral; 0.1% to 0.5% by weight, preferably 0.2% by weight of a hydrogel; and 39.5% to 39.9% by weight, preferably 39.8% by weight of water (in each case based on the total amount of the building material).

[0040] Preferably, the present adhesive building material comprises an acrylic-based hydrogel. Thus, the hydrogel is formed from cross-linked polyacrylates called superabsorbers and water, which do not release the water stored in the hydrogel immediately, but gradually release it to the surrounding swellable clay minerals, and thus cause swelling with a delayed effect.

[0041] In a particularly preferred embodiment, copolymers of acrylic acid and acrylic acid esters are used as at least one hydrogel or absorbent. Such acrylic absorbents with a particle size between 100 μm and 1000 μm are also called superabsorbents and are able to absorb many times their own weight of polar liquids, such as water. Once the liquid has been absorbed, the superabsorbent swells and forms a hydrogel.

[0042] In another embodiment of the present adhesive building material, the expandable clay mineral is selected from the group consisting of bentonite, montmorillonite, kaolinite, montmorillonite, illite, chlorite or mixtures thereof.

[0043] Bentonite, named after the Benton Formation, Fort Benton Montana, is a rock composed of a mixture of various clay minerals and contains montmorillonite as its most important component (60% to 80%), which explains its strong water absorption and swelling. Other associated minerals are quartz, mica, feldspar, pyrite or calcite. Bentonite is formed by the weathering of volcanic ash.

[0044] A well-known representative of clay minerals is montmorillonite, which belongs to the montmorillonite family and is a dioctahedral three-layer silicate having a tetrahedral layer-octahedral layer-tetrahedral layer structure and a high degree of swelling.

[0045] Mixed layers can structurally include very different alternating layers, such as kaolinite / montmorillonite, chlorite / vermiculite, mica / vermiculite or often alternating illite / montmorillonite or illite / montmorillonite layers. Thus, compared with pure montmorillonite, the exchange reactions of cations and anions are possible to be more diverse. Therefore, mixed layers combined with other active minerals are particularly well suited for the binding of substances in solution in biological systems.

[0046] Currently, expandable clay minerals having a particle size between 1 mm and 20 mm, preferably between 5 mm and 18 mm, more preferably between 10 mm and 16 mm are used.

[0047] The present viscous building material (or sealing material) is preferably produced by mixing the listed ingredients or components at the construction site and shortly before use.

[0048] In this process, first, a) a virtually puncture-proof, non-drip hydrogel is prepared and provided by cross-linking polyacrylates and water, and then, b) swellable clay mineral particles are added to the provided hydrogel while mixing, whereby the clay particles are wetted with the hydrogel in a largely non-destructive manner.

[0049] The adhesive sealing or building material produced in this way has a firm, brittle consistency and a moisture content of 15% to 50%.

[0050] In this way, the building material can be mixed according to the recipe in an integrated mixing unit, for example a drum mixing unit or a shaft mixing unit, and introduced into the filling pipe in portions according to the drilling cross section and the drilling depth.

[0051] The clay particles are irregularly surrounded by solid hydrogel particles filled with water. These hydrogel particles release water under pressure, whereupon the water enters or diffuses into the swellable clay, which swells as a result and becomes a dense, homogeneous clay mass. Thus, after application in the borehole, a solid, partly elastic and partly plastic sealing mass is formed by the automatic expansion of the contained swellable clay minerals without the need for further addition of water.

[0052] The advantage of using a building material or sealing material in this case is that after the building material or sealing material is produced and inserted into the drilled hole, after a short time the sealing material has soil-mechanical properties and characteristics similar to the surrounding rock or soil, in particular with regard to moisture and density.

[0053] Compacting thus has two purposes: the pressure during compaction causes water to enter the middle layers of the clay material, causing it to swell and return to a density close to that which it had before opencast mining. In addition, building materials are compacted in layers in a borehole using the method according to the invention.

[0054] Due to its good soil-mechanical properties, this viscous building material or sealing material can also be used as an elastic-plastic mineral seal in well construction, pipeline construction, for the sealing of gas wells, the sealing of storage depots and mines, and as a moisture barrier in structural sealing.

[0055] The conveying device for filling and compacting the drilled hole in the method comprises at least one push chain unit, which comprises a push chain drive and a filling piston driven by means of the push chain drive.

[0056] In one embodiment, at least one filling piston is arranged on a push chain of a push chain drive via a connecting rod connection. In this case, the push chain has a supporting effect; the filling effect is caused by the piston's own weight. The filling piston can be made of, for example, stainless steel or a suitable metal alloy.

[0057] The packing piston has a cylindrical shape, so the length of the piston is preferably at least twice the bore diameter; i.e., a smaller bore diameter prefers a shorter piston, while a larger bore diameter prefers a longer piston. Using a disc as a packing piston is undesirable because there is a risk that the disc will get stuck in the bore.

[0058] The conveying device can be mounted on a vehicle or on a construction machine. For example, the conveying device can be mobile, preferably mounted on an all-terrain vehicle, mounted on a tracked chassis so that the conveying device can be moved independently, or mounted on a frame that is moved by a construction machine such as a wheel loader or a forklift. This allows different positioning of the conveying device. For example, the conveying device can be positioned on a vehicle or on a construction machine above the borehole to be filled. Another variant is that the conveying device is transported on a vehicle to the vicinity of the filling point, unloaded from the vehicle using a crane provided on the vehicle, and positioned, for example, above the borehole to be filled.

[0059] In one embodiment, a chain driven transport vehicle is used.Alternatively, the transport vehicle can travel on railway tracks or can be towed by a drilling excavator.

[0060] A construction kit is arranged on the transport device, which enables the push chain unit located on the transport device to be moved in a rotatable and transversely extendable manner. The effective radius should preferably be up to 2 meters around the center point (around the X / Y axis). Such an attachment can be, for example, a rotatable cross table.

[0061] The transmission device of the device is preferably a hydraulic transmission device.

[0062] Furthermore, a receiving frame is provided on the transport device, which comprises a drive chain unit with a drive chain and a vertical transmission (Z axis). The control of the Z axis is coordinated with the rotational movement of the X / Y axis and preferably takes place via a joystick.

[0063] The conveying device is preferably attached to or connected to a receiving frame and can be arranged as a unit with the receiving frame on a transport device (eg for transport purposes) or can also be used separately from a transport device (eg directly at a filling point).

[0064] The push chain unit can have a vertical height adjustment (along the Z axis) of up to 2 m above the top edge of the terrain. The height adjustment enables the pulled-out filling tube to be easily lowered when the filling piston is at the upper stop.

[0065] In addition, the conveying device has a device for positioning the filling piston above the filling tube. The filling tube and the filling piston are controlled by means of laser (green diode 575nm, red diode 650nm); the filling piston is positioned above the filling tube by positioning the laser.

[0066] Before the filling piston compresses the filling material by pressure, the filling tube must be pulled out of the drilled hole to the height of the installation layer. The building material must not be compacted in the filling tube. The push chain is suitable for pulling the filling tube because the push chain is already in the filling tube. Accordingly, according to other embodiments, a device is provided for pulling the filling tube out of the drilled hole in response to the backfilling of the drilled hole. The device can be arranged on a rigid push chain as a drive hook or a brake device. These hooks or brake devices are connected to the filling tube and allow the filling tube to be pulled out of the drilled hole when the push chain is slowly moved.

[0067] The jaw clamp is used to pull the filling tube out of the drill hole. The jaw clamp, for example, clamps the filling tube to be pulled out at the thread, pulls the filling tube and closes the filling tube after the filling tube is pulled out.

[0068] In other embodiments, the device has a quick-change unit (as an excavator attachment). For this purpose, the receiving frame is connected to a rotating device, such as a tilting device. Such a tilting device enables the receiving frame including the push chain unit to be quickly separated from the transport device and used as a single device on the excavator.

[0069] In other embodiments, the production device has a control technology for controlling the push chain drive. The control technology of the push chain drive measures the increase in counterpressure of the packing piston at the corresponding position in the borehole by means of a sensor (pressure sensor). In addition, the control technology controls the packing movement of the packing piston by means of an appropriate reciprocating movement and in this way compacts the cohesive earth material in the borehole.

[0070] In other embodiments, the conveyor device has an interface with the control system, via which electronic data on compaction, installed quantity and geographical location can be provided. This enables electronic quality documentation.

[0071] In one embodiment, the control technology controlling the push chain unit also provides the following data via the data interface:

[0072] o Geo-locate backfill boreholes via GPS coordinates, output longitude and latitude, e.g.

[0073] Record in the form of QR code;

[0074] oDate and time;

[0075] o Compression level = location of the deepest drill hole, given in m below the top edge of the terrain;

[0076] o Groundwater level in the borehole, given in m below the top edge of the terrain;

[0077] o The contact pressure during backfilling and compaction of the layer, given in SI units, e.g. N / sqm;

[0078] oThickness of the compacted layer, given in m below the top edge of the terrain;

[0079] o Further acquisition of geophysical important measurements and data such as water quality (salinity) through sensors;

[0080] oManual entry of additional numeric and alphanumeric data / free text at the control unit's terminal.

[0081] A camera optionally installed in the filling piston provides photographs that supplement the data set. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The present invention will be described in detail below by way of examples with reference to the accompanying drawings. In the accompanying drawings:

[0083] Figure 1 is a first schematic illustration of the method;

[0084] Figure 2 is a second schematic illustration of the method; and

[0085] Figure 3 is a schematic illustration of an embodiment of a push chain unit used in this example;

[0086] Figure 4 is a schematic illustration of an embodiment of the present delivery device; and

[0087] Figure 5 is a schematic illustration of another embodiment of the conveying device. DETAILED DESCRIPTION

[0088] Figure 1 The process step of first filling of the drilled hole is shown. The viscous building material 18 is produced in a shaft mixer or rotary mixer and filled in portions into the drilled filling tube 15 or protective tube (step a).

[0089] The filling piston 14 connected to the push chain 17 of the backfilling machine pushes the building material to the bottom of the drilled hole through the filling pipe 15. The push chain 17 is the drive unit of the machine, which pushes and pulls the filling piston 14. As the backfilling progresses, the filling pipe 15 is pulled out of the drilled hole. A first layer of compacted backfill material 19 is formed at the bottom (step b).

[0090] Figure 2 The further steps a) to c) are shown, which produce the layer-by-layer filling of the borehole and the compaction of the viscous building material in the borehole. The push chain 17 together with the filling piston 14 is moved out of the filling tube 15, the filling tube 15 is filled with the next portion of sealing material 18, and the filling piston 14 is reinserted into the filling tube 15.

[0091] This process of partially filling and compacting the viscous building material 18 in the drilled hole is repeated until the drilled hole is completely filled and flush with the ground surface or ground edge.

[0092] Figure 3 An embodiment of a push chain unit 13 according to the invention is schematically shown. The push chain unit 13 comprises a push chain 17 with a push chain drive and a filling piston 14 driven by means of the push chain drive.

[0093] Figure 4 An embodiment of a filling device 10 according to the present invention is schematically shown, the filling device 10 comprising Figure 3 The push chain unit 13 with the filling piston 14 and the filling tube 15 is shown in FIG.

[0094] The push chain unit 13 is part of a mounting frame which is arranged (horizontally) on the chain-driven transport device 11. For this purpose, a mounting kit (not shown) is arranged on the transport device, which enables the push chain unit located on the transport device to be moved in a rotatable and transversely extendable manner (along the X / Y axis).

[0095] The push chain unit can have a vertical height adjustment (along the Z axis) of up to 2 m above the top edge of the terrain. The height adjustment enables the pulled-out filling tube 15 to be easily lowered when the filling piston 14 is at the upper stop.

[0096] The receiving frame 12 is connected to a rotating device 16, such as a tilting device. Such a tilting device 16 enables the receiving frame 12 including the push chain unit 13 to be quickly separated from the transport device 11, so as to be able to be applied as a single unit on an excavator.

[0097] Figure 5 Schematically shows another embodiment of the filling device 10 according to the present invention, the filling device 10 comprises Figure 4The push chain unit 13 shown in FIG. 1 has a filling piston 14 and a filling tube 15, which is connected to the receiving frame 12. Figure 5 In contrast to the embodiment in FIG. 1 , a receiving frame 12 with a push chain unit 13 is arranged vertically on a piece of construction equipment as a transport device 11 .

[0098] Figure 5 The construction equipment shown in also has a rotary lifting device 20. This makes it possible to transport the conveying device on the construction equipment to the vicinity of the filling point and to position the conveying device including the receiving frame 12, the push chain unit 13 with the filling piston 14 and the filling tube 15 above the drill hole using the rotary lifting device.

[0099] The jaw clamp 21 is used to pull the filling tube out of the drill hole. The jaw clamp 21 clamps the filling tube to be pulled, for example, at the thread, pulls the filling tube and closes the filling tube after the filling tube is pulled out.

[0100] Example 1: Compaction method for boreholes used for explosive ordnance sounding

[0101] The explosive ordnance detector drills holes with a diameter of 100mm to 130mm in a grid of approximately 1.20m×1.20m, usually 6m deep. After drilling, the detector inserts the detection protection tube into the hole. The detection protection tube is a PE or PVC tube, usually 56mm in diameter and 6m long, and the detection protection tube can also include threaded sections.

[0102] The detector guides the magnetically sensitive measuring instrument on the cable into the protective tube to the deepest point of the borehole. After completing the measurement, the detector leaves the cased borehole until the backfilling machine fills the borehole.

[0103] The crawler-driven all-terrain backfiller is positioned above the drilled hole. The detection protection tube previously inserted into the drilled hole has a slightly larger diameter of 94 mm / 104 mm (inner diameter / outer diameter) and consists of segments screwed together, each segment is 1.50 m long, and is filled with a certain amount of sealing material, which can be determined by means of metering technology (casting trough, screw conveyor, sliding gate or similar device). The detection protection tube is here a filling tube.

[0104] A filling piston, which is attached to the push chain of the backfilling machine by means of a joint, is inserted into the filling pipe and driven by the push chain. This pushes the building material through the filling pipe until the deepest part of the drilled hole is reached. The control technology of the push chain drive measures the increase in counterpressure at the corresponding position of the filling piston by means of a sensor (pressure sensor) and switches from "fast stroke" to "slow stroke = compaction". The control technology realizes the filling movement of the filling piston by means of an appropriate reciprocating motion and in this way compacts the cohesive earthwork material.

[0105] As the filling and compaction proceed layer by layer, the filling tube is pulled in. This means that compaction takes place outside (= below) the filling tube, ie at the deepest point of the drilled hole.

[0106] The push chain with the filler piston is moved out of the filler tube, the filler tube is filled with the next portion of sealant, and the filler piston is reinserted into the filler tube.

[0107] Every 3 layers, a section of the filling pipe is unscrewed. With a pipe length of 6 m (corresponding to the depth of the borehole), this results in 12 push chain strokes and a backfill distance of 50 cm per layer and compaction. Finally, the borehole is filled and compacted layer by layer, and the 6 m borehole depth then has 12 compacted layers of 50 cm each.

[0108] Travel time of the push chain without compaction travel (assumption: down travel = same length as pulling time)

[0109]

[0110]

[0111] For a 6m deep borehole and 12 layers, the sum of the travel times of the push chains is about 300 seconds, i.e. about 6 minutes. This is quite reasonable, and the time budget for the entire backfill is 15 minutes per borehole.

[0112] Example 2: Bonding building materials / sealing materials

[0113] formula:

[0114] 1 ton of building materials includes:

[0115] 60% = 600 kg expandable clay (particle size 1mm to 16mm, preferably 5mm to 16mm)

[0116] 39.8% = 398 liters of water

[0117] 0.2% = 2.0kg hydrogel powder

[0118] The building material mixture should be prepared on site shortly before installation. It is possible - but not yet tested - that the mixture can also be delivered pre-mixed (such as concrete in a concrete mixer truck).

[0119] manufacture:

[0120] Step 1: According to the present invention, hydrogel powder is placed in a mixing container / mixer / blender in an amount of 0.2% of the total amount of building materials.

[0121] Step 2: Add about 40% of water depending on the amount of building material and mix / stir slowly (do not mix colloidal or dispersive like with a TP-type homogenizer (Ultraturrax)!) until a no longer dripping, almost cut-resistant, slippery and crumbly gel is obtained.

[0122] Step 3: Clay particles corresponding to 60% of the total amount of building materials were added and mixed by stirring.

[0123] The result: Clay particles are irregularly surrounded by water-filled solid particles (these particles look like crushed gummy bears). According to the invention, these hydrogel particles release water under pressure, so that the water enters the swellable clay, which then swells and becomes a dense, homogeneous clay mass.

Claims

1. A method for filling and compacting a viscous building material layer by layer in at least one borehole near the ground surface, wherein: The viscous building material is introduced into the at least one drilled hole and compacted layer by layer using a conveying device, the conveying device comprising a push chain drive and a filling piston driven by means of the push chain drive; Said cohesive building material for filling and compacting a borehole comprises at least one absorbent in the form of a hydrogel and a compactable soil building material; The hydrogel is acrylic-based; The soil building material is a swellable clay mineral selected from the group consisting of bentonite, montmorillonite, kaolinite, montmorillonite, illite or chlorite or a mixture thereof.

2. The method according to claim 1, characterized in that The at least one drill hole is lined with a protective tube and the viscous building material is partially filled into the drill hole with the protective tube.

3. The method according to claim 1, characterized in that After the first portion of the viscous building material is filled into the drilled hole, the filling piston of the conveying device pushes the viscous building material in the drilled hole to the corresponding lowest depth of the drilled hole and compacts the viscous building material by the vertical movement of the filling piston.

4. The method according to claim 2, characterized in that: During the filling of the drilled hole with the viscous building material, the protective tube is withdrawn from the drilled hole stepwise according to the amount of the viscous building material introduced.

5. The method according to claim 3, characterized in that: After compacting the first portion of the viscous building material in the at least one borehole, the filling piston is moved out of the borehole, another portion of the viscous building material is filled into the borehole, the filling piston is reintroduced into the borehole and the another portion of the viscous building material is compacted by the movement of the filling piston.

6. The method according to claim 1, characterized in that The compactable soil building material is selected from expandable clay minerals, excavated soils or excavated bored materials.

7. The method according to claim 1, characterized in that To produce the adhesive building material, first, a) a hydrogel is prepared by crosslinking polyacrylate and water, and then, b) swellable clay mineral particles are added to the hydrogel while mixing, so that the clay particles are wetted with the hydrogel.

8. The method according to claim 7, characterized in that The produced viscous building material has a firm, crumbly consistency and a moisture content of 15% to 50%.

9. The method according to claim 1, characterized in that: The cohesive building material is a cohesive soil building material.

10. A conveying device (10) for filling and compacting drilled holes in a method according to claim 1, the conveying device (10) comprising at least one push chain unit (13), the push chain unit (13) comprising a push chain drive and a filling piston (14) driven by means of the push chain drive.

11. The conveying device according to claim 10, characterized in that The at least one filling piston is arranged on a push chain of the push chain drive via an articulated connection.

12. The conveying device according to claim 10, characterized in that Control technology for controlling the push chain drive.

13. The conveying device according to claim 12, characterized in that: Electronic data on compaction, installed quantities and geographic location is provided via an interface with the control technology.

14. The conveying device according to claim 10, characterized in that The conveying device is installed on a vehicle or construction equipment as a transportation tool or is used separately from the transportation tool.

Images