EP0672794A1 - Deep stratum compacting device - Google Patents

Abstract

The deep compressor is for the compression of deeply located ground layers and has a shaft with which a compression member is connected in one-piece construction. The compression member (14) is formed by at least two equal downwardly hanging compression fingers (20), between which a yoke (18) extends. The compression fingers are formed cylindrically and at their lower ends terminate in a cone (40). The cones have a cone angle of more than 90 deg., partic. approximately 135 deg. The compression fingers have an internal width between them which partic. corresponds to double their dia. They have a length which in partic. is seven to eight times their dia.

Description

The invention relates to a deep compactor for compacting deep-lying soil layers, according to the preamble of claim 1.

Soil compactors have become known in numerous modifications. For example, a soil compactor has become known from DE-AS 20 59 644 which, by means of a pendulum arm, sets a pressure plate which can be placed on a ballast surface in vibration, with both horizontal and vertical vibrations in the soil surface, which in the present application are caused by a ballast bed of a track is formed, can be introduced. Such compressors are well suited when surface layers have to be compacted, for example when ballast is applied to a well-bearing deep layer. Because of the tips on the compaction elements, the compaction element penetrates somewhat into the ballast surface in this known solution.

However, there is often the problem that the load-bearing capacity of the subsoil is no longer sufficient due to increased traffic loads. This applies both to new lines and when upgrading to higher-quality track systems, for example if a track line is to be made ICE-compatible, or if heavy goods freight traffic is now to be used.

In these cases, it is necessary to compact the deep-lying base layers, for which purpose the upper layers, possibly including the ballast bed already lying down, have always been removed and each layer at the height of e.g. 30 to 50 cm has been compacted separately.

On the one hand, this method is very labor-intensive and time-consuming, and on the other hand, it is not possible if there is heavy traffic in the immediate vicinity of the track running on a parallel track. In such cases, one has often used auxiliary constructions by namely a sheet pile or sheeting is provided, which requires additional effort.

Furthermore, it is known from US Pat. No. 3,865,501 to provide a generic depth compressor with a shaft to which a compression element is connected. In this solution, the shaft is vibrated and the compression is carried out via six or eight plates protruding in a star shape on a tube on the outside, which form the compression element and are set into resonance vibrations for compression. In order not to generate too high a compression during the penetration, the oscillation frequency is halved at this time and the resonance frequency is only activated at the desired target depth, which should be 30 m or more.

A disadvantage of this solution is that the compression element is often difficult to remove after compression has taken place, especially since the resonance vibrations produce compression zones in the area immediately adjacent to the wings.

A further problem exists with floors which have a granular basic structure, so that resonance vibrations can only be transmitted poorly due to the strong damping through the floors. In such cases, the solution according to US Pat. No. 3,865,501 provides for the transmission forces to be increased by adding water. However, this measure does not succeed if, for example, a water-impermeable layer, such as a clay layer, lies above the layer to be compacted, so that the layer underneath cannot then be sufficiently compacted. While the compacting effect in the solution according to the aforementioned US patent is good with a uniform soil structure, it is unsatisfactory with a layered soil structure, for example when loose granular layers alternate with tougher layers (clay, etc.).

Furthermore, from DE-AS 21 25 732 a ballast compacting machine is known, which is said to be particularly suitable for generating a compression of the ballast across thresholds with several vibration peaks. The entire unit can be pivoted about a pivot point S. In the area of a yoke above a threshold, two counterbalance unbalance motors are arranged, each of which acts via pressure plates on a wedge-shaped transverse connecting bar with which the compression is to be achieved. This solution is mechanically very complex due to the synchronous and counter-rotating unbalance motors, which have to be stored in a rather stable manner. Special measures must be taken so that individual coarse stones of the ballast do not get caught on the pressure plates that work against the yoke that supports the unbalance motors. In addition, deep compaction cannot be achieved with this solution.

In contrast, the invention has for its object to provide a depth compactor according to the preamble of claim 1, which is less sensitive to the soil structure and with which a reliable depth compaction is possible without the application of any cover layers such as a ballast bed.

This object is achieved by claim 1. Advantageous further developments result from the subclaims.

According to the invention, the compression element has at least two essentially identical compression fingers hanging downward. The compression is surprisingly good in the area between the compression fingers and in the area adjacent to it, the degree of compression benefiting from the fact that the compression fingers first cause horizontal pre-compression when the depth compactor penetrates and the following Yoke, even if it is not led down into the compression area itself, achieves vertical post-compression due to the pressures generated via its ramming surface. The structural independence of the depth compactor according to the invention is improved due to the combination of horizontal and vertical compaction forces, and even in the case of granular soil there is no lateral deflection of the areas to be compacted after they have been gripped like pliers by the at least two downwardly extending compression fingers.

According to the invention, the fact that several compression fingers are of the same design can be used particularly advantageously. The progress of compaction can overlap, so that the rearmost compression finger is always inserted into the hole left by the foremost compression finger. Lateral deflection of the layers to be compressed is then reliably prevented, it being understood that, if desired, the rearmost compression finger can be made longer than the other compression fingers. It is also possible to insert an elastically or at least movably suspended protective tube into the foremost hole of the previous compaction process, so that the current compaction process does not result in soil material being pressed into the previously created hole.

Compared to the known solutions, the invention is characterized in that the soil material is compressed in deep areas after it is surrounded on three sides by the compaction element according to the invention. Due to the impacts, for example, of a ram on the shaft of the deep compressor, the compression element is not only driven downwards. Rather, vibrations of the compression fingers are generated at their natural frequency, which also contribute to the compression and which make it easier to pull out the depth compressor.

The compression fingers can be either conical or cylindrical, with a polygonal cross section basically also being possible. The taper can be chosen so that it is not necessary for the yoke to touch the ground. The cylindrical configuration with a cone at the end, which has an obtuse cone angle, is preferred. The cone causes a pre-compression, which is stronger the larger the cone angle, but this reduces the working speed. Accordingly, the cone angle should be significantly below 180 °, for example at 120 to 150 °.

The degree of compression is also influenced by the distance between the compression fingers in relation to their diameter. With already pre-compacted soil, only a few compacting fingers with a small diameter - based on their distance - need to be used. However, the diameter of a compression finger should not be less than one eighth of the distance between the compression fingers in order to ensure effective compression. In this context, it is advantageous if both the number, the arrangement and the configuration of the compression fingers can be adapted to the desired conditions. According to one embodiment of the invention, it is therefore provided that the compression fingers are releasably attached to the yoke.

The ratio between pre-compression and post-compression can also be adjusted via the length of the compression fingers. The post-compaction is advantageously carried out via a ramming surface at the bottom of the yoke, which is preferably V-shaped, so that the penetration of the yoke into the ground is facilitated. There is also the possibility of using a downward-facing T-beam as the ramming surface, the crossbar of the T then acting as the ramming surface.

The depth compressor according to the invention is not for use limited when compacting gravel foundations. Rather, it is possible to use the deep compaction according to the invention in all areas of earthworks, for example for the creation of embankment fillings, the creation of terrain cuts for the consolidation of the depth layers and the creation of subsurfaces to be consolidated for road construction, but also for example for soil improvement . If the method of deep compaction according to the invention is used, the footprint can be improved, for example for drilling platforms or similar structures, and loads from high-rise structures can be absorbed in a structurally simplified manner if, according to the invention, the soil pressure is increased by the deep compaction.

Furthermore, it goes without saying that not only natural soil can be compacted, but also, for example, backfill materials such as ground or broken concrete or slag materials and even corresponding plastics. The deep compaction according to the invention is also not restricted to the dry area; rather, it can also be used successfully in water-bearing layers and, if desired, also below water-bearing horizons.

It is particularly expedient that, according to an advantageous embodiment of the depth compressor according to the invention, a vibrating hammer or a vibration exciter can be used, the speed of which can be regulated. The frequency of the vibrations introduced can thus be controlled within wide limits, which leads to corresponding control options for the expansion of the vibration field in all directions. As a result, the degree of grain rearrangement effected according to the invention can also be controlled, which has direct effects on the density and load-bearing capacity of the mass processed according to the invention.

In a further preferred embodiment of the invention, it is provided that two or several vibration exciters are provided. These can be controlled individually, which means that the cycle sequence of the vibrations introduced can be increased, and can also be controlled synchronously with one another, which increases the power of the vibrations introduced and emitted. Such a system can be used particularly cheaply if several vibration fingers are used not only next to each other, but in at least two levels, that is to say one behind the other. With this type of design of the depth compressor according to the invention, it is possible to utilize the vibrations which have been introduced several times in such a way that the soil located in the space between the vibration fingers under the vibration exciters is subjected to particularly strong compaction. Due to the vibrations introduced, the compaction fingers are also deflected horizontally, with the surrounding earth being particularly strongly compacted.

Instead of or in addition to the preferably provided vibration rams, which tend to work at low frequencies, high-frequency vibration exciters can be used with success, any interferences generated particularly promoting grain redistribution and thus compaction due to the existing vibration maxima.

Further details, features and advantages result from the following description of an exemplary embodiment with reference to the drawings.

Fig. 1

eine etwas schematisierte Seitenansicht eines erfindungsgemäßen Tiefenverdichters;

Fig. 2

einen Schnitt durch eine weitere Ausführungsform eines erfindungsgemäßen Tiefenverdichters, unter Darstellung des unteren Endes eines Verdichtungsfingers in teilweise aufgebrochener Ansicht; und

Fig. 3

eine Ansicht entlang der Linie III-III aus Fig. 2.

It shows:

Fig. 1

a somewhat schematic side view of a depth compressor according to the invention;

Fig. 2

a section through a further embodiment of a depth compressor according to the invention, showing the lower end of a compression finger in part broken view; and

Fig. 3

a view along the line III-III of Fig. 2nd

A depth compressor 10 has a shaft 12 and a compression element 14, which consists of a yoke 18 and, in the case of the present exemplary embodiment, four compression fingers 20. The yoke 18 is welded to the shaft 12, the connection between the yoke 18 and the shaft 12 being additionally reinforced by means of anti-kink bars 22 and 24, which run obliquely between the shaft and the yoke. The shaft 12 consists of a solid tube and has at its clamping end a receptacle 26 for a vibration hammer known per se. It goes without saying that other suitable recordings can also be used instead of the image shown. However, the receptacle must also be able to transmit tensile forces in order to be able to remove the deep compactor from the ground after compaction has taken place. If the receptacle is moved to both sides to loosen the driven deep compressor to prepare for pulling out, the connection between yoke and shaft is subjected to bending. In this case, the anti-kink bars 24 are used, which are welded so that they are able to absorb the respective kinking forces under tensile load.

The yoke 18 is designed as a crossbar and has receptacles for the compression fingers 20 on its underside. The compression fingers 20 can either be welded to the yoke or be held interchangeably in stable plug receptacles. In any case, it is preferred to provide a bearing both at the lower end 30 and at the upper end 32 of the plug-in receptacle 34, so that any lateral moments can be well supported. Lateral moments can penetrate into the soil through different soil structures on the compression fingers 20, so that it is advantageous if the height of the plug receptacle 34 and not less than a tenth of the length of the compression finger 20 and preferred is about a quarter of this length if the compression fingers 20 are detachable, or an eighth if the compression fingers 20 are welded.

The yoke according to the invention has at its lower end laterally between the compression fingers 20 each stamping surface 36, which are essentially V-shaped, so that a penetration edge 38 results at the bottom of the yoke 18. The angle of the V can be between approximately 90 and 150 °, it being understood that any other suitable configurations are possible, for example also a radius or a corresponding taper between the plug-in receptacles 34 over the width of the yoke 18. In the example, the distance is of the two middle compression fingers 20 is less than the distance between a middle and the outer compression finger. This configuration produces the strongest compression in the middle, ie below the shaft 12. It goes without saying that, instead of this, it is also possible for the compression fingers 20 to be attached in a grid-like manner, and also that the number of compression fingers 20 is selected according to the requirements and can even be eight or ten, for example.

Each compression finger has a cone 40 at its lower end, with which the tube forming the compression finger 20 is closed at the bottom. The cone 40 facilitates the penetration of each compaction finger 20 into the ground.

In operation, the deep compressor 10 is moved either in the drawing direction or laterally. When moving in the direction of the drawing, it is preferred that the holes created in one compression process are filled with crushed stone or the like before the next compression process is initiated, so as to prevent them from collapsing due to the subsequent compression process. When moving laterally, however, an overlapping progression can also be selected, so that the area to be compacted is always bracketed on the side and cannot break out.

In a modified embodiment of the depth compressor 10 according to the invention, it is provided to provide at least one injection nozzle 42 at the tip of at least one compression finger 20. It goes without saying that more than one compression finger 20 can also be used and that more than one injection nozzle 42 per compression finger 20 is also possible. Furthermore, it goes without saying that, in addition to the closable configuration of the injection nozzle 42 shown here, an unlocked configuration is also possible, in particular if an injection nozzle 42 is used with a deflecting surface which does not easily clog when the vibrations or vibrations according to the invention are introduced.

According to the exemplary embodiment shown here, an injection nozzle 42 has a plurality of individual nozzles 44, 46, 48, which are each arranged on the circumference and at the lower end of the compression finger 20. The individual nozzles 44, 46, 48 are each vertically slit-shaped, so that they offer only a small additional friction in relation to their cross-sectional area when compressing according to the invention via the vibrations introduced. In the exemplary embodiment shown, the individual nozzles 44, 46, 48 end with the upper edge of the tip cone 40 of the compression finger 20 and extend approximately 15 cm upwards. A plurality of individual nozzles 44, 46, 48 are provided, which are each distributed around the circumference of the compression finger 20, without a uniform distribution being absolutely necessary.

The injection nozzle 42 has a closure 50 with which it can be closed. Even if a twist lock can basically be used and only requires a slight twist due to the vertical orientation of the slots 44 to 48, in the illustrated embodiment there is one axially displaceable closure is provided, which consists essentially of a cylinder, which rests on the inner circumference of the compression finger 20. The closure 50 rests on the bottom of a deflecting cone 52, which is attached opposite the tip cone 40 at the lower end of the compression finger 20 and serves to discharge the injection material located inside the compression finger 20.

To guide the closure 50, control pins 54 are welded to the inner circumference of the compression finger 20, the design of which can be seen in the plan view from FIG. 3. The control pins 54 cooperate with two control elements 56, which are mounted opposite one another on the inner circumference of the closure 50. Since the holding forces for the inertial mass of the closure 50 have to be supported due to the vertical vibrations, it is more favorable to use two anchoring elements and control elements 56 lying opposite one another.

In the normal state, the control elements 56 cause a lock between the closure 50 and the compression finger 20. When a control cable 58 is pulled, the connection is released and the closure 50 can be raised via the same control cable 58 to such an extent that the injection nozzle 42 is released completely. In the exemplary embodiment shown, only one control cable 58 is used, and the further control element 56 is connected to the opposite control element 56 by means of drivers 60, so that a pivoting movement of the control element 56 about its axis 62 also leads to a correspondingly symmetrical pivoting movement of the opposite control element 56. The control element 56 is basically designed as a lever disk, the configuration from FIG. 3 being more clearly visible. The control element 56 has a locking latch 64 at its lower end, which engages behind the control pin 54. Control 56 is strongly chamfered at the top and bottom, but also laterally, so that it has small contact surfaces for the penetrating injection material.

The axis 62 supports the lever disk or the control element 56 on the closure 50. As can be seen in FIG. 3, the closure 50 is provided in the region of the latch 64 and below it with a slot 66 which widens upwards and then tapers . The widening of the slot 66 allows the lateral deflection of the lever disk 56 when pulling on the control cable 58. The dead weight of the closure 50 is so great in relation to the weight of the control element 56 that when pulling on the control cable 58, which is at a pivot point 68 on the Lever washer 56 is articulated, the lever washer 56 is first pivoted clockwise, so that the latch 64 is released from the control pin 54. The locking pin 54 has an upper inclined surface 70, which facilitates the deflection of the lever disk by pivoting the locking latch 64 when the lock 50 is lowered again. A corresponding inclined surface 72, which is designed for sliding on the inclined surface 70, is located at the bottom right of the locking latch 64. The slot 66 also runs towards the inclined surface 70 at the top. In the closed state of the locking latch 64, the control pin 54 is clamped between the locking latch 64 and the upper inclined surface of the slot 66, it being understood that the relevant seating surfaces can, if desired, be coated with damping material, such as a rubber layer. However, it must be ensured that a free pivoting of the latch 64 is not impaired by the seat material.

The illustrated embodiment only requires the use of a control cable 54 for the provision of the locking function as well as for the lifting of the closure 50. It goes without saying that, if desired, instead of the one control cable 58, two opposite control cables can also be attached to the two control elements 56.

Furthermore, it goes without saying that the closure 50 can be extended beyond the axial length in the exemplary embodiment shown in order to minimize the tendency to tilt due to the control cable 58 attached on one side when it is pulled up. Furthermore, it goes without saying that the drivers 60 do not have to be chamfered as shown, but can also be formed only as round wires.

When assembling a control element 56 according to the invention, it is preferred to first introduce the closure 50 together with the control element 56 before the deflection cone 52 and then the tip cone 40 is welded on. However, it goes without saying that the unit consisting of deflecting cone 52 and tip cone 40 can instead be screwed onto the lower end of the compression finger 20 if free access to the closure 50 is to be made possible for maintenance purposes.

Furthermore, it goes without saying that any other suitable closure can also be used instead of the closure shown. For example, the cone surfaces of the tip cone 40 can be pivoted so that the injection material, which is under hydraulic pressure inside the compression finger 20, enables the tip cone to be opened. When the finger is pulled out, the tip cone then remains open and can be closed mechanically or, if desired, also by means of an appropriate electromagnet after removal.

Claims (17)

Depth compactor for compacting deep-lying soil layers, with a shaft to which a compacting element is connected in particular in one piece, characterized in that the compacting element (14) is formed by at least two essentially identical, downwardly hanging compacting fingers (20), between which there is a Yoke (18) extends. Depth compressor according to claim 1, characterized in that the compression fingers (20) are substantially cylindrical and end at their lower end in a cone (40) which has a cone angle of preferably more than 90 °, in particular about 135 °. Depth compactor according to claim 1 or 2, characterized in that the compression fingers (20) are arranged with a clear width from each other which corresponds to one to four times, in particular twice, their diameter. Depth compressor according to one of the preceding claims, characterized in that each compression finger (20) has a length which corresponds to three to twenty times, in particular seven to eight times its diameter. Depth compressor according to one of the preceding claims, characterized in that four to eight, in particular four, compression fingers (20) are provided next to one another, the distance between the two middle compression fingers (20) being less than the distance between the middle compression fingers (20) and the lateral compression fingers (20 20) is. Depth compactor according to one of the preceding claims, characterized in that the yoke (18) extends across all of the compaction fingers (20) and at the bottom has a ramming surface (36) which is suitably designed for penetration into the ground and in particular tapers downwards . Depth compactor according to one of the preceding claims, characterized in that the compaction fingers (20) are detachably attached to the yoke (18) and the number and thickness of the compaction fingers (20) can be adapted to the degree of pre-compaction of the soil layers to be compacted. Depth compactor according to one of the preceding claims, characterized in that the shaft (12) is additionally connected to the yoke (18) by means of anti-kink bars (22, 24), with which an uneven loading of the compression fingers (20) due to different ground conditions and a possible lateral force can be caught when pulling out the depth compressor (10). Depth compressor according to one of the preceding claims, characterized in that the clamping end of the shaft (12) is suspended from a vibrating ram via which the deep compactor (10) can be driven into the ground with an adjustable driving sequence, in particular between 8 and 0.5 beats per minute. Depth compactor according to one of the preceding claims, characterized in that the vertical height of the lower edge (38) of the yoke is approximately 40 to 90%, preferably 50 to 70% and in particular approximately 60% of the distance between the clamping end of the shaft (12) and the lower one End of the compression finger (20). Deep compactor according to one of the preceding claims, characterized in that the width of the deep compactor (10) is 20 to 150%, preferably 50 to 90% and in particular approximately 70% of the distance between the clamping end of the shaft (12) and the lower end of the compression fingers ( 20) is. Depth compressor according to one of the preceding claims, characterized in that the shaft (12) is connected to a vibration exciter whose frequency can be controlled. Depth compressor according to one of the preceding claims, characterized in that the compression element (14) is connected to two or more vibration exciters which are controlled either independently of one another, out of phase with one another or synchronously with one another and act on vibration fingers (20) located below the vibration exciter, whereby In particular, a shaft (12) is assigned to each vibration exciter and each vibration exciter preferably acts on a level of compression fingers (20). Deep compactor for compacting deep-lying soil layers, with a shaft to which a compacting element is connected, characterized in that the compacting element (14) is formed by at least one downwardly hanging hollow compacting finger (20), which is an injection nozzle (42). Depth compressor according to one of the preceding claims, characterized in that an injection nozzle (42) is provided at the bottom of a compression finger (20) and can be closed by a closure (50) while vibrations are being introduced into the compression element (14). Depth compressor according to claim 15, characterized in that the closure (50) has a control, with which it can be opened either by the pressure of injection material or by mechanically or electromechanically acting control elements (56) as required and can be controlled so that it can be controlled during the Pulling out the compression finger (20) remains open. Depth compressor according to one of the preceding claims, characterized in that a hollow compression finger (20) is used as a line for injection material, such as cement, and the shaft (12) has a hydraulic connection via which the injection material is hydraulically connected via the injection nozzle (42) the floor can be pressed in.

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