AU2017242643B2

AU2017242643B2 - Drilling method and shaft drilling system

Info

Publication number: AU2017242643B2
Application number: AU2017242643A
Authority: AU
Inventors: Niko Kleuters
Original assignee: Nk Trading And Eng GmbH
Current assignee: NK TRADING AND ENGINEERING GmbH
Priority date: 2016-04-01
Filing date: 2017-03-30
Publication date: 2020-01-23
Anticipated expiration: 2037-03-30
Also published as: EP3436664A1; WO2017167856A1; CN109072696B; CN109072696A; AU2017242643A1; ZA201805981B; EP3436664B1

Abstract

The invention relates to a boring method in which overburden in a shaft end of a drilled shaft (10) is created by a drill unit (90). The overburden is transferred by means of liquid into a container (30, 40) provided within the drilled shaft (10). A mixture of overburden and liquid is thus located in the container (30, 40). The container (30, 40) is flooded by further transfer of overburden by means of liquid, wherein at least excess liquid overflows. A residual mixture remains in the container (30, 40). The liquid that has overflowed is returned to the shaft end. The residual mixture is transported away through the drilled shaft (10). By way of this special separation method, free spaces are created in the region of the drill unit (90), which, even in the case of relatively small shaft diameters, for the first time allows effective, safe and commercially advantageous drilling operation in full shaft drilling mode. The invention also relates to a shaft drilling system which is suitable for carrying out the drilling method.

Description

Drilling method and shaft drilling system

The present invention relates to a drilling method with overburden removal carried out by means of liquid and to a shaft drilling system for carrying out such a drilling method.

Known drilling methods generally comprise the following steps. A drill unit is provided, which is arranged in a shaft to be drilled at a shaft end of the drilled shaft and configured to substantially create overburden by drilling by removing rocks and ground soil. For example, the removal additionally takes place by means of blasting or using another suitable technique 0 to expand or deepen a drilled shaft.

In known methods, the created overburden is collected by means of liquid, such as water, and the resulting mixture is transported to the surface, i.e. into the region surrounding the drilled shaft opening. This generally takes place by means of a pump system or an air lift system. Occasionally, 5 scraper systems or vacuum suction systems were also used. This has the disadvantage that the capacity of the pump system must be high with increasing depth of the drilled shafts and that there is also the risk of this pump system clogging. Such a malfunction can only be eliminated again with great effort. The elimination of such a malfunction is particularly difficult when shaft access is impeded because of a small shaft diameter of 3 m to 8 m. Scraper systems are subject to high wear 0 and tear in abrasive mountain conditions and also require too much space. Vacuum systems have a very high energy requirement and require a large-volume installation, e.g. dry separation, in the shaft. High waste heat values are produced, which in turn require large-volume cooling systems. In the case of water inflow, scraper and vacuum systems are ineffective, for example.

At the surface, liquid is generally once again removed from the mixture and then conducted back into the shaft end since liquid is constantly needed there in order to transport away overburden.

Often times, shafts with a small diameter of 3 m to 8 m are expanded by transporting away the overburden via an already existing pilot hole and/or shafts, with all of the aforementioned 30 disadvantages. Moreover, the necessity of a pilot hole always implies additional work, time and thus also costs in order to be able to efficiently expand a drilled shaft after all. It implies a lot of effort to provide the logistics for overburden transport under ground.

The sinking of shafts in the given diameter range without a pilot hole is mostly carried out in 35 conventional blasting operations or by means of the so-called air lift method. Both methods have key disadvantages in terms of sinking speed, project duration, safety and costs.

In the air lift method, the drilled shaft is, for process-related reasons, completely filled with liquid up

2017242643 09 Dec 2019 to the shaft collar during the drilling work. The sinking speeds are very low, in particular in hard formations, and the direction accuracy is limited. In difficult, brittle formations, additives must be added to the liquid column in order to prevent an uncontrolled flowing off of the liquid into the surrounding mountain formation. This is often times very time-consuming and expensive and can 5 only be controlled insufficiently. The shaft wall lining can only be introduced subsequently.

Alternatively, shafts are also sunk in a blasting process. The respective disadvantages are sufficiently known. For example, the sinking speed decreases with increasing shaft depth. As a result of the formation of blasting cracks, the surrounding geological formations can be 0 affected and there is an increased safety risk for personnel at the shaft bottom.

Even when taking into consideration the increasingly stricter international safety regulations, there is therefore a need in mining for a more efficient, safer drilling method and a shaft drilling system that can be used more efficiently.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Disclosed herein is a drilling method comprising:

- Arranging a drill unit at a shaft end of a drilled shaft;

- Producing overburden by means of a drill unit;

- Providing a container for the overburden within the drilled shaft;

- Transferring the overburden into the container by means of liquid so that a mixture of overburden and liquid is located in the container;

- Flooding of the container by further transfer of overburden by means of liquid, wherein at least excess liquid overflows and a residual mixture with a high overburden portion remains in the container;

- Returning the overflowed liquid into the shaft end; and

- Transporting away the residual mixture through the drilled shaft.

Also disclosed herein is a shaft drilling system comprising:

2017242643 09 Dec 2019

- a drill unit that is to be arranged in a drilled shaft and is designed to remove overburden at a shaft end of the drilled shaft,

- a container that is arranged in the drilled shaft and is suitable for receiving a mixture of overburden and liquid,

- a transfer system, for example a pump system, for transferring the overburden by means of liquid into the container, wherein the container is flooded and a residual mixture remains in the container, and

- a lifting system that is suitable for transporting the residual mixture through the drilled shaft.

According to one or more embodiments disclosed herein, a drill unit is arranged at a shaft end of a drilled shaft during a drilling process. The drilled shaft may have a minimum diameter of 3 m to 8 m, preferably 5 m, for example.

According to one or more embodiments disclosed herein, overburden is created by means of the 5 drill unit by drilling removal. Optionally, overburden can additionally be created by means of blasting.

According to one or more embodiments disclosed herein, a container for the overburden is provided in the drilled shaft; this container is in particular suitable for collecting a mixture of overburden and liquid. According to one or more embodiments disclosed herein, the overburden 0 is transferred by means of liquid into the container so that a mixture of overburden and liquid collects in the container. To this end, a transfer system, for example a pump system, may be provided.

In embodiments, both the drill unit and the container are arranged within the drilled shaft. An 5 arrangement within the drilled shaft is to be understood to be an arrangement in which the container is located permanently or at least during the duration of the filling operation in the volume provided by the void volume of the shaft. The container is preferably arranged closer to the shaft end than to the drilled shaft opening. For example, the distance between the drill unit and the container is less than 10 m. As a result of this arrangement, the necessary pump capacity 30 may be considerably reduced.

Preferably, the overburden collecting in a bottom region of the shaft end after removal by the drill unit is wetted so that the mixture of overburden and water as liquid is produced there. For example, the mixture of overburden and liquid may be pumped from the shaft end (from the 35 shaft floor) into the container.

According to one or more embodiments disclosed herein, the container is flooded with the mixture, wherein at least excess liquid overflows from the container. Preferably, the overflowing

2017242643 09 Dec 2019 liquid is received by an overflow gutter or an overflow arranged in or on the container. The flooding takes place by additional transfer of overburden into the container by means of liquid loaded with overburden. Within the container, the heavier overburden at least partially deposits on the bottom and the liquid floats on top. Coarser overburden sinks more quickly in the 5 container than fine-grained overburden, for example. By flooding the container, i.e. by filling beyond the maximum fill height, also called maximum holding capacity, excess liquid is displaced from the container and further overburden deposits in the container. As a result, the liquid portion in the residual mixture remaining in the container decreases. The overburden portion in the container is increased by sedimentation, while the liquid portion in the container is 0 reduced. Since the overburden furthermore does not have a homogeneous composition but mostly coarser and finer components, the loose filling of larger components of the overburden forms intermediate spaces, in which smaller components of the overburden can settle so that a denser mixture can furthermore be achieved overall as the finer components can accumulate between the coarser components in the container.

Depositing of the overburden requires a certain amount of time, which is given by the duration of the filling operation. It can be said that the longer the filling operation takes, the denser the mixture can become since there is more time for the overburden to deposit. The duration of the filling operation is determined by the transfer speed and by the maximum holding capacity of the 0 container. Ideally, these two parameters are adapted to each other in order to achieve a good compromise between the efficiency of the drilling operation and the consistency of the mixture.

According to one or more embodiments disclosed herein, a return of the excess or overflowing liquid into the shaft end (to the shaft floor), in particular into the bottom region, takes place 5 during the drilling process in order to wet further accumulating overburden there.

One or more embodiments of the drilling method disclosed herein comprise the step of transporting away the residual mixture through the drilled shaft.

It is an excellent advantage of one or more embodiments disclosed herein that liquid loaded with fine components in the hollow spaces of the coarse overburden in the container is also transported away from the shaft floor. This prevents an increasing sludge accumulation in the liquid on the shaft bottom, which could otherwise at least considerably impair the pumpability of the liquid mixture. One or more embodiments disclosed hereinmanage without the provision of the customary large-volume separation elements, which in turn results in crucial space advantages on the shaft bottom in the case of smaller shaft diameters. The liquid level at the shaft floor can be controlled by supplying clean/separated liquid through a hollow guiding track. Without this advantage, the efficient and safe automatic drilling of blind shafts with smaller

2017242643 09 Dec 2019 diameters would continue to be unresolved.

In an advantageous embodiment of the drilling method disclosed herein, excess liquid is first received by an overflow gutter arranged in or on the container, before it is returned. For 5 example, the overflow gutter is formed circumferentially on the edge of the container.

In another advantageous embodiment of the drilling method disclosed herein, excess liquid is returned via a down pipe. For example, the down pipe runs along a shaft wall, in particular on the inside from a filling platform at the upper end of the drill unit along a machine-related shaft 0 wall support device. A possibly provided overflow gutter in particular opens into the down pipe.

In another embodiment of the drilling method disclosed herein, the residual mixture (of the liquid mixture pumped from the shaft floor) is transferred from the container into a separate 5 (additional) conveying container, which is also arranged in the drilled shaft. The container then fulfills the function of a collecting container, in particular of a stationary collecting container. A residual mixture with a high overburden portion is first produced in the collecting container as a result of overflow and return of excess liquid. The transfer takes place, for example, by the collecting container being arranged above the conveying container and a 0 ramp forming by opening a flap in the bottom of the collecting container. Via this ramp, the residual mixture is conveyed from the collecting container into the conveying container.

Another embodiment of the drilling method disclosed herein comprises the unloading of the mixture or the emptying of the conveying container outside the drilled shaft and the return 5 transport of the conveying container into the drilled shaft, in particular into a loading position for resuming the individual method steps.

This embodiment allows further overburden to be transferred by means of liquid into the collecting container, while the conveying container transports away the residual mixture. The 30 efficiency of transporting away the residual mixture and thus also the shaft sinking speed are considerably increased in this way.

During all of the aforementioned method steps, there is the possibility of the drill unit removing further overburden and of an advance of the drilled shaft being driven independently of the 35 conveying cycle of the container. Alternatively, the removal of the overburden can be paused during all or even only during individual method steps in order to protect other equipment arranged in the shaft end, for example.

2017242643 09 Dec 2019

In another advantageous embodiment of the invention, the container itself is the conveying container that can be transported away through the drilled shaft. Alternatively, the conveying container can also be another (additional) element as described above in connection with the container designed as stationary collecting container.

As already mentioned further above, in the drilling method disclosed herein, the residual mixture is transported away through the drilled shaft. The residual mixture may be transported away in the conveying container.

In another advantageous embodiment of the invention, the method furthermore comprises the step of emptying the conveying container outside the drilled shaft. This takes place, for example, in a collecting bin, in which the overburden of the mixture can deposit further. After treatment, liquid floating on top can then also be returned again to the shaft floor. Additional measures for dewatering the mixture, such as sifting processes, are conceivable.

In yet another advantageous embodiment of the invention, the method moreover comprises the step of returning the emptied conveying container into the drilled shaft.

The transporting away of the residual mixture can, for example, take place via a pulling rope 0 and a lifting system. The lifting system may be arranged outside the drilled shaft and may comprise a rope winch, onto which the pulling rope is rolled up, whereby the conveying container is transported through the drilled shaft. Differently designed lifting systems are also conceivable and included within the meaning of the invention. A lifting system within the meaning of the invention may be suitable for transporting the mixture, also called residual 5 mixture, through the drilled shaft, in particular in the conveying container. The lifting system may also be suitable for returning the conveying container into the drilled shaft.

Preferably, the conveying container is arranged circumferentially to a central longitudinal axis of the drilled shaft. This arrangement is in particular suitable in drilled shafts with a rather 30 small diameter of less than four meters (< 4 m) and correspondingly limited available space within the drilled shaft. The risk of contact of the container and the shaft wall may in this way reduced or prevented and/or he volume capacity of the container may be increased.

The container can in particular be designed and arranged such that its center of gravity, in 35 particular when empty and also when filled with a homogeneous filling, is not located on the central longitudinal axis of the drilled shaft. As a result of the center of gravity being located outside the shaft axis, the guiding forces for the transport of the container may be reduced.

2017242643 09 Dec 2019

Preferably running along the central longitudinal axis of the drilled shaft is a central guiding track and/or lifting track, which serves at least to lift the drill unit and, for example, furthermore as supporting attachment for those devices that are provided to supply the equipment arranged in the drilled shaft, such as electrical lines and/or liquid supply lines and/or liquid 5 discharge lines. The supply lines, etc. are preferably protected by covers attached to the guiding track. These covers are preferably designed such that they simultaneously serve as guide rails for the container during conveying operations.

The container preferably comprises a recess designed such that the central guiding track can 0 extend therein. For example, the container may comprise a recess extending from the container opening to the container bottom in the longitudinal direction of the container. The cross section of the recess may in particular be designed in the shape of a U. In a drilled shaft, the recess results in an effectively space-filling arrangement of the container around the central guiding track. The provision of the recess furthermore ensures a shifting of the center of gravity 5 in relation to the non-recessed container. It is achieved thereby that the container can transport itself in a stabilizing manner along the guiding track on a pulling system, such as a pulling rope.

The guiding forces are thereby reduced and very advantageous higher conveying speeds can be achieved. This means that the center of gravity of the conveying container, in particular when empty and also when filled with a homogeneous filling, is not located on the central longitudinal 0 axis of the drilled shaft, which facilitates pulling up on a pulling rope that runs at an offset to the central guiding track and allows correspondingly higher conveying speeds; accordingly, the shaft sinking speed is also increased. The emptying of the conveying container by tipping relatively to the central guiding track is also made possible by the recess, without the conveying container having to be completely detached from the guiding track. Holding 5 elements to which the conveying container is attached in an articulated manner and thus in a manner tippable about a swivel axis are preferably arranged on the conveying container.

The drilling method according to one or more embodiments disclosed herein is in particular suitable for application in a drilled shaft designed to be substantially vertical.

According to an advantageous embodiment of the container, into which the mixture of liquid and overburden is pumped, the upper cross-sectional opening of the container comprises a lattice. The lattice is preferably arranged below the overflow. The lattice serves as coarse filter and, according to the mesh width, hinders the coarser drill cuttings from getting out of 35 the container again. The mesh width can preferably be changed according to the consistencies of the drill cuttings. For supplying the mixture of liquid and overburden, a corresponding opening is provided in the lattice. The opening can alternatively also be formed by the lattice not covering the entire cross-sectional opening of the container. This coarse

2017242643 09 Dec 2019 filter is cleaned as soon as the supply of the mixture is interrupted or stopped.

According to a preferred embodiment, the lattice is designed such that at least individual lattice ribs are designed to be elongated and protrude into the container. This additionally 5 calms the liquid mixture, which is turbulent as a result of the filling operation, and accelerates the deposition process of the overburden.

In yet another advantageous embodiment of the invention, at least one working platform is provided within the drilled shaft. From the working platform, personnel can perform works within 0 the drilled shaft and need not go into the flooded bottom region of the drilled shaft. The working platform is preferably arranged circumferentially to the central guiding track within the drilled shaft. In this way, a maximum size of the working platform with correspondingly optimized available working space can be achieved. The supply of the personnel with sufficient breathing air is facilitated by an appropriate supply through the free inner cross section of the guiding 5 track.

According to another advantageous embodiment, the platform is arranged movably along the central guiding track. In particular, the platform may be arranged below the container surrounding the central guiding track. It is preferably held by the container. For example, the 0 working platform is connected to the container via trusses. For lack of space, it is advantageous when the container is both conveying and collecting container. In the two-part embodiment of the container, the working platform can however also be arranged below the conveying container. In embodiments in which the container is moved along the central guiding track, the working platform also moves.

In another embodiment, the working platform is designed to transport and hold other equipment within the drilled shaft. For example, another drill unit may be arranged on an underside of the working platform. The working platform may therefore in particular be suitable for installing a shaft lining on the shaft wall from there. For example, the shaft lining may consist of pre30 assembled plates (so-called liner plates) that can be expanded to a cylindrical tube. The preassembled plates may be transported from the surface around the central guiding track onto the working platform in the drilled shaft. There, the shaft lining may be expanded by means of a suitable tool and pressed onto the shaft wall. This system can also be automated without the need for personnel in the drilled shaft. The use of shaft wall support plates pre-assembled on 35 the surface and their possibly automated installation are only possible in embodiments of the described drilling system since no other interfering supply lines of any type are arranged outside the central guiding track.

2017242643 09 Dec 2019

A protective cover is preferably arranged between the working platform and the container in order to protect persons and equipment that are located on the working platform.

As a result of the advantageous use of available space within the drilled shaft for arranging conveying and collecting containers and as a result of the partial dewatering of the mixture of overburden and liquid already taking place in the drilled shaft, embodiments of the drilling method described may be particularly suitable for sinking shafts without the need of a hollow space already existing under ground as a target. Such a drilling method can also be called full shaft drilling or blind shaft drilling.

Embodiments of the described shaft drilling system allow for an innovative drilling method, with which particularly smaller full shaft drillings and blind shaft drillings of between approx. 3 m and 8 m diameter can be sunk more efficiently, more quickly and safely for the personnel. Embodiments of the system provide a simple separation and conveyance of drill cuttings in comparison to all previous systems. At the same time, the special arrangement of drilling machine or drill unit, the drill cuttings separation and the drill cuttings removal guided centrally in the shaft allow for an effective shaft wall construction directly above the drilling machine / drill unit. The shaft wall is permanently actively supported by the respective construction until stabilization. Even in the case of smaller drilling diameters, the particular arrangement provided by embodiments of the innovative assemblies provides sufficient free space to temporarily install a drilling device in the shaft above the drilling machine in order to carry out borehole detections and anchoring and consolidation work. The drilling machine is preferably connected to the lifting device on the shaft collar via a segmented guiding track and can thus be pulled to the shaft collar as needed without prior disassembly, e.g., in the case of possible water inflows, other emergencies and for the purposes of disassembly after completion of the shaft. The respective connection may also serve as guide for the cage and as guide and support for the supply lines. Via the open inner cross section of the guiding track, the region of the drilling machine on the shaft bottom can be supplied with water and air as needed. The particular arrangement of the machine elements of one or more embodiments makes it 30 possible to install a prefabricated shaft wall lining directly above the drilling machine in the case of smaller shaft diameters, since the shaft cross section outside the guiding track can be kept completely free (i.e. no supply lines, etc.).

Embodiments of the invention are explained in more detail with reference to the following figures. 35 The figures are only to be understood as examples and merely constitute preferred design variants, which are explained in more detail below with reference to the drawing and are not to restrict the invention. The invention is not restricted to the described exemplary embodiments; it can also include other design variants that utilize the invention. In the drawing, the following is

2017242643 09 Dec 2019 shown schematically:

Fig. 1 a partial view in longitudinal section of an exemplary embodiment of a shaft drilling system according to the invention within a drilled shaft for carrying out an exemplary 5 embodiment of a drilling method according to the invention,

Fig. 2 a partial view in longitudinal section of another exemplary embodiment of a shaft drilling system according to the invention within a drilled shaft for carrying out another exemplary embodiment of a drilling method according to the invention,

Fig. 3 a top view of an arrangement of a collecting container and a conveying container of the shaft drilling system of Fig. 1,

Fig. 4 a top view of an arrangement of a collecting container and a conveying container of the 5 shaft drilling system of Fig. 2,

Fig. 5 a partial view of the shaft drilling system of Fig. 2 on a surface outside the drilled shaft,

Fig. 6 a partial view in longitudinal section of yet another exemplary embodiment of a shaft 0 drilling system according to the invention within a drilled shaft for carrying out another exemplary embodiment of a drilling method according to the invention,

Fig. 7 a top view of a shaft lining for a drilled shaft prior to installation on the drilled shaft, and

Fig. 8 a top view of the shaft lining of Fig. 7 after its installation on the drilled shaft.

Parts that are equivalent with respect to their function are always provided with the same reference symbols in the different figures so that these parts are generally also only described once.

Fig. 1 shows a shaft drilling system for carrying out a drilling method according to a first exemplary embodiment of the invention. The individual elements of the shaft drilling system and the individual method steps are explained in more detail below.

Shown is a cross section through a shaft end of a vertical drilled shaft 10. Within the drilled 35 shaft 10, a central guiding track 60 is arranged along the central longitudinal axis of said shaft.

Furthermore arranged in the shaft end is a drill unit 90 designed to further advance the drilling of the drilled shaft 10 and to remove overburden. This is carried out, for example, by means of a

2017242643 09 Dec 2019 rotating drill head or using any other suitable mechanized technique for expanding and/or deepening the drilled shaft 10. In the bottom region 12 of the shaft end, the removed overburden collects. The drilled shaft 10 is wetted in the bottom region 12 of the shaft end so that a mixture of overburden and liquid is located there.

A container 20 is arranged above the drill unit 90. In the exemplary embodiment shown, the container 20 is designed as collecting container 30. It is suitable for receiving the mixture of overburden and liquid from the bottom region 12.

Arranged in the drilled shaft 10 between the drill unit 90 and the collecting container 30 is a conveying container 40. The latter is preferably designed and/or arranged to be circumferential to the central guiding track 60.

Also arranged in the shaft end is a pump system 50. The pump system 50 comprises a pump, a pipe 54 and a supply line 52. The pipe 54 extends to the bottom region 12 of the shaft end, in which the mixture of overburden and liquid is located. The supply line 52 is connected to the collecting container 30. The supply line 52 is, for example, conducted along a shaft wall. The mixture of overburden and liquid is transferred into the collecting container 30 via the supply line 52 by means of the pump system 50. There, at least a part of the overburden deposits by sedimentation at the bottom in the collecting container 30 and the liquid floats substantially on top.

Circumferentially around the collecting container 30 and adjacently to the shaft wall, an overflow gutter 25 is formed. When the maximum holding capacity of the collecting container 30 is reached, excess liquid flows from the collecting container 30 into the overflow gutter 25.

From there, the excess liquid is once again conducted to the bottom region 12 of the shaft end. This takes place via a down pipe 22, which is arranged along the shaft wall. Alternatively, excess liquid could, for example, flow out of the overflow 25.

In its bottom, the collecting container 30 comprises a flap 35. By opening the flap 35, a ramp 30 forms between the collecting container 30 and the conveying container 40, via which ramp the residual mixture finds its way from the collecting container 30 into the conveying container 40. This takes place during a pause of the pump or when the liquid mixture is pumped into another container 30 arranged in this region, i.e. when the transfer of overburden by means of liquid into the collecting container 30 stops and after the collecting container 30 was flooded.

The conveying container 40 is guided thereafter along and preferably through the central guiding track 60 and transported away in the direction of an upper shaft opening. This takes place via the pulling rope 70. The pulling rope 70 is preferably moreover designed to hold the

2017242643 09 Dec 2019 conveying container 40.

A drilling method that is carried out by means of such an arrangement comprises the steps described below.

A liquid/overburden mixture is preferably produced by drilling on the shaft bottom. The mixture of overburden and liquid is pumped or transferred from the bottom region 12 of the shaft end into the collecting container 30. The pumping takes place until the maximum holding capacity of the collecting container 30 is reached and beyond. The collecting container 30 is flooded by 0 the additional pumping. Excess liquid flows out of the collecting container 30 into the overflow gutter 25 and is again returned from there into the bottom region 12 of the shaft end. A residual mixture remains in the collecting container 30.

If only one collecting container 30 is provided, the pumping must be interrupted at least 5 temporarily in order to transfer the residual mixture from the collecting container 30 into the conveying container 40. The parameter(s) that result in the interruption of the pump can be of different types. For example, the time determines how long the pumping operation lasts. Alternatively, the amount of liquid that has already flown from the collecting container 30 as a result of flooding can be detected. If this amount of liquid reached a predefined amount, the 0 pumping operation is interrupted. Alternatively or additionally, the weight of the filled collecting container 30 can be determined. For example, a maximum weight is provided.

During the pause of the pump, the flap 35 in the bottom of the collecting container 30 is opened so that the residual mixture accumulated there can be transferred into the conveying 5 container 40. The opened flap 35 in this case forms a ramp between the collecting container and the conveying container 40.

If at least two collecting containers 30 are arranged, the pump line is swiveled over the second collecting container 30 and fills it, while the content of the first collecting container 30 30 is transferred into the conveying container. As a result, pauses of the pump are avoided and/or reduced and the shaft sinking speed increases.

In another method step, the filled conveying container 40 is transported away in the direction of the upper shaft opening by means of the pulling rope 70.

When the collecting container 30 and the conveying container 40 are two different units as in the exemplary embodiment shown in Fig. 1, a new transfer of overburden by means of liquid can already take place when the conveying container 40 is transported in the direction of the

2017242643 09 Dec 2019 upper shaft opening. As a result, the efficiency of transporting away the overburden or the residual mixture is increased.

In the exemplary embodiment shown in Fig. 2, the container 20 is both collecting container 30 and conveying container 40. The other elements shown substantially correspond to the elements described and shown in Fig. 1. The embodiment of the container 20 such that it simultaneously designed as the collecting container 30 and the conveying container 40 means a space saving in the drilled shaft 10 and is in particular suitable for drilled shafts 10 of smaller diameters, in particular of diameters less than four meters (4 m). As described, it is possible and advantageous in the case of larger shaft diameters to arrange one or more collecting containers 30 (as interim overburden storage), which allow a continuous drilling cycle with corresponding higher sinking rates in the case of the higher overburden production corresponding to the diameter.

A drilling method carried out by means of such an arrangement comprises the following steps:

Drilling with the following pumping of the overburden/liquid mixture from the bottom of the drilled shaft 10 into the collecting container 30 or into the conveying container 40 until its maximum holding capacity is reached and beyond; returning the liquid overflowed into the overflow gutter 25 into the bottom region 12 of the shaft end; and interrupting the pumping operation during the transporting away of the container 20 designed as collecting container 30 and/or conveying container 40 through the drilled shaft 10. When the container 20 is once again arranged in a suitable position in the drilled shaft 10, the method can be resumed.

Fig. 3 shows a top view of an arrangement of a collecting container 30 and a conveying container of the shaft drilling system of Fig. 1. The collecting container 30 is arranged in a lateral region of the drilled shaft 10 on the shaft wall. In the center of the collecting container 30, an overflow gutter is formed, via which excess liquid can flow off. The central guiding track 60, which extends along the central longitudinal axis of the drilled shaft 10, can also be seen. Around this central guiding track 60, the conveying container 40 is arranged. In the exemplary embodiment shown, the base area of the conveying container 40 is designed to be substantially rectangular. The conveying 30 container 40 moreover comprises a U-shaped recess 26, which extends around the central guiding track 60. The recess 26 extends from a container opening to a container bottom.

Fig. 4 shows a top view of a container 20 of the shaft drilling system of Fig. 2 arranged in a drilled shaft 10. The container 20 is simultaneously designed as collecting container 30 and as 35 conveying container 40. It has a substantially round base area, which comprises a U-shaped recess 26. The container 30 or 40 is arranged coaxially to the longitudinal axis of the drilled shaft

10. The central guiding track 60 extends within the U-shaped recess 26 of the container 20.

2017242643 09 Dec 2019

As a result of the U-shaped recess 26, the center of gravity of the container 30 or 40 shifts from the central position, especially when said container is filled. This means that the center of gravity of the container 30 or 40 is not located on the central longitudinal axis of the drilled shaft 10 but in the pulling center of the conveyor rope. As a result, the pulling up of the container 30 5 or 40 on the pulling rope 70, which runs at an offset to the central guiding track 60, is facilitated and the guiding forces between the container 30 or 40 and the pulling rope 70 are minimized.

Emptying the container 30 or 40 by tipping relatively to the longitudinal axis of the drilled shaft 10 is also made possible by the U-shaped recess 26.

Fig. 5 shows how emptying at the surface can take place. Moreover shown is an exemplary embodiment of the lifting system 80, which is arranged at the surface. The container 30 or 40 is transported on the pulling rope 70 through the drilled shaft 10. To this end, the pulling rope 70 is rolled onto or off a winch. Arranged on the container 30 or 40 are detachable guiding elements / 5 holding elements 72, which allow a tipping of the container 30 or 40 in order to empty it. The container 30 or 40 must in this case not be detached from the central guiding track 60.

Fig. 6 shows another advantageous development of the shaft drilling system of Fig. 2. For transporting away the overburden, only one container 20 is provided, which is conveying 0 container 40 and collecting container 30 at the same time. Below the container 30 or 40 is arranged a working platform 100. The working platform 100 is connected to the container 30 or 40 by means of trusses 102. If the container 30 or 40 moves along the central guiding track 60, the working platform 100 also moves. The container 30 or 40 is shown in several positions along the central guiding track 60, the working platform 100 as well. The working platform 100 is arranged 5 at a distance to the container 30 or 40. The distance is in particular no more than 1.50 m so that a person can stand on the working platform 100 at least in a stooped position. Between the working platform 100 and the container 30 or 40, a protective cover 105 is additionally arranged in order to protect persons and equipment on the working platform 100. From the working platform 100, a shaft lining 110 can be installed. The working height of the platform 100 is preferably dimensioned 30 such that work to be done can be carried out comfortably and in an upright position by personnel.

Fig. 7 shows a top view of a shaft lining 110 within the drilled shaft 10 prior to final assembly. The shaft lining 110 consists of pre-assembled plates. The plates run helically above one another and can be expanded to a cylinder with the diameter of the drilled shaft 10. On the 35 outside of the tube or shaft lining 110 are located flexible spacers 112, which ensure safe contact to the shaft wall even with the arising shaft diameter tolerances. The shaft lining 110 can be expanded by means of a suitable tool 108, for example a hydraulic cylinder. The shaft lining 110 is pressed onto the shaft wall. A support structure 115 is located on the shaft wall.

2017242643 09 Dec 2019

The support structure 115 serves to hold the shaft lining 110. Sidewalls and longitudinal connections are connected to each other in order to ensure a stable shaft lining.

Fig. 8 shows the shaft lining 110 of Fig. 7 after it is completely installed. The flexible spacers 5 112 are in this case in direct contact with the shaft wall. Alternatively or additionally, they can also be in contact with the support structure 115.

Claims

1. A drilling method comprising:

- Arranging a drill unit at a shaft end of a drilled shaft;

2. The drilling method according to the preceding claim, furthermore comprising:

- Collecting the overflowed liquid in an overflow gutter, in particular in an overflow gutter arranged in or on the container.

3. The drilling method according to any one of the preceding claims, wherein the return of 0 overflowed liquid takes place through a down pipe.

4 The drilling method according to any one of the preceding claims, wherein the container is a stationary collecting container, and furthermore comprising:

- Transferring the residual mixture from the container into an additional conveying

5 the drilled shaft so that it serves as conveying container and as collecting container.

5. The drilling method according to any one of the preceding claims 1 through 3, wherein the container is a conveying container that can be transported away through the drilled shaft.

«.5 container that is arranged in and can be transported away through the drilled shaft.

5 - Producing overburden by means of a drill unit;

- Providing a container for the overburden within the drilled shaft;

I

- Flooding of the container by further transfer of overburden by means of liquid,

0 wherein at least excess liquid overflows and a residual mixture with a high overburden portion remains in the container;

- Returning the overflowed liquid into the shaft end; and

- Transporting away the residual mixture through the drilled shaft.

5

6. The drilling method according to claim 4 or claim 5, wherein the transporting away of the residual mixture takes place in the conveying container.

7. The drilling method according to any one of claims 4 to 6, furthermore comprising:

35 - Emptying the conveying container outside the drilled shaft.

8. The drilling method according to claim 7, furthermore comprising:

- Returning the emptied conveying container into the drilled shaft.

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9. The drilling method according to any one of the preceding claims, wherein the transporting away of the residual mixture takes place by means of a pulling rope.

5

10. A shaft drilling system comprising

0 - a transfer system, for example a pump system, for transferring the overburden by means of liquid into the container, wherein the container is flooded and a residual mixture remains in the container, and

11. The shaft drilling system according to the preceding claim, wherein the container comprises an overflow gutter.

12. The shaft drilling system according to the preceding claim, wherein the overflow gutter

0 opens into a down pipe.

13. The shaft drilling system according to the preceding claim, wherein the down pipe is conducted along a shaft wall.

5

14. The shaft drilling system according to any one of the preceding claims 10 through 13, wherein a central guiding and/or lifting track, at least for lifting the drill unit, extends along a central longitudinal axis of the drilled shaft.

15. The shaft drilling system according to any one of the preceding claims 10 through 14,

30 wherein the container is arranged to surround a central longitudinal axis of the drilled shaft.

16. The shaft drilling system according to the preceding claim, wherein the container is designed and arranged such that its center of gravity, in particular when the container is

35 empty, is not located on the central longitudinal axis of the drilled shaft.

17. The shaft drilling system according to claim 15 or claim 16, wherein the container comprises a recess, preferably a recess with a U-shaped cross section, which recess

2017242643 09 Dec 2019 extends from a container opening to a container bottom.

18. The shaft drilling system according to any one of the preceding claims 10 through 17, wherein the container is part of the lifting system and can be transported away through

19. The shaft drilling system according to any one of the preceding claims 10 through 18, wherein the container is attached to and/or guided on the central guiding track.

0

20. The shaft drilling system according to any one of the preceding claims 10 through 19, wherein the container is a stationary collecting container and wherein an additional conveying container is arranged in the drilled shaft.