Method for stabilizing an earth formation

Abstract

In a method for stabilizing an earth formation exposed after removal of a track and ballast, in a first working pass in a work section following a rear crawler track with regard to a working direction, parallel to the removal of the ballast the earth formation is loosened up, aggregates are introduced, and grading takes place. In a second working pass, the earth formation to which aggregates have been added is mixed thoroughly by getting picked up by means of a clearing chain and transported onward to a discharge point located behind the rear crawler track and discharged again upon the exposed earth formation, after which, by grading and consolidating the discharged earth formation, a rehabilitation layer is formed.

Claims

1. A method for stabilizing an earth formation of a track, wherein the earth formation, exposed after removal of the track and ballast, is mixed with aggregates and leveled and consolidated, thus forming a protection layer, comprising the following features: a) in a first working passin a work section adjoining a rear crawler track with regard to a working directionparallel to the removal of the ballast the earth formation is loosened up, aggregates are introduced, and grading takes place, b) in a second working pass, the earth formation to which aggregates have been added is mixed thoroughly by getting picked up by means of a clearing chain and being transported onward to a discharge point located behind the rear crawler track and being discharged again upon the exposed earth formation, after which, by grading and consolidating the discharged earth formation, a rehabilitation layer is formed.

2. The method according to claim 1, wherein the ballast picked up in the first working pass is cleaned and gravel, which has been separated out as spoil in the process, is intermediately stored, said gravel being discharged in the second working pass upon the rehabilitation layer and graded to form a protection layer.

3. The method according to claim 2, wherein, prior to the discharging of gravel, a foil is placed upon the rehabilitation layer.

4. The method according to claim 1, wherein the ballast picked up by the clearing chain is cleaned and, after intermediate storage, discharged upon the rehabilitation layer to form a ballast bed.

5. A machine having crawler tracks, a clearing chain for picking up ballast, a screening installation, and a discharge device provided for introducing bulk material, for carrying out a method for stabilizing an earth formation of a track according to claim 1, comprising the following features: a) behind a rear crawler trackwith regard to a working direction of the machinea bulk material store having a discharge opening for aggregates is arranged as said discharge device, b) arranged in front of the bulk material store are scarifying teeth, spaced from one another in a transverse direction of the machine and vertically adjustable by drives, for loosening up an earth formation, c) behind the bulk material store, with regard to the working direction, a grading- and consolidating device is provided.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantages of the invention become apparent from the remaining dependent claims and the drawing description.

(2) The invention will be described in more detail below with reference to an embodiment represented in the drawing.

(3) FIGS. 1 and 2 each show a side view of a machinedepicted during two different working passesfor carrying out the method according to the invention.

DETAILED DESCRIPTION

(4) A machine 1 shown in the drawing, serving for subgrade rehabilitation of a track, has a machine frame 2 which is equipped with two on-track undercarriages 3 arranged at the ends. Between these, a front crawler track 5 and a rear crawler track 6with regard to a working direction 4are connected for vertical adjustment via drives 7 to the machine frame 2, on which are additionally provided a clearing chain 8 for picking up ballast 9, a screening installation 10, a work cabin 11, and a motor 12.

(5) At the rear end of the machine frame 2, a discharge device 22 in the shape of a bulk material store 13 having an outlet opening 14 is arranged which is followed, with regard to the working direction 4, by a grading- and consolidating device 15. Located in front of the bulk material store 13 is a scarifying device 17, vertically adjustable by drives 16, which has scarifying teeth 18 spaced from one another in a transverse direction of the machine.

(6) The method, according to the invention, for stabilizing an earth formation 19 of the track commencesafter the dismantling of rails and sleepers of the track has taken placewith the removal of the ballast 9 by means of the clearing chain 8 in a first working pass depicted in FIG. 1. During this, the machine 1 is moved continuously by means of the lowered crawler tracks 5 and 6 on the earth formation 19 exposed by the preceding clearing chain 8. The ballast cleaned in the screening installation 10 and the spoil accruing in the process are loaded via conveyor belts 23 for intermediate storage into material wagons (not shown) located on the adjacent track.

(7) Parallel thereto, in a work section 20 adjoining the rear crawler track 6 with respect to the working direction 4, the earth formation 19 is loosened up by means of the scarifying teeth 18 and mixed with aggregates 30 (such as a lime-cement mixture, for example) which are introduced via the outlet opening 14 of the bulk material store 13. Immediately thereafter, the earth formation 19 is leveled by means of the grading- and consolidating device 15 and compacted, thus forming a protection layer 21.

(8) In a second working pass depicted in FIG. 2, the earth formation 19 mixed with the aggregates 30 is now picked up by means of the clearing chain 8 and transported onward via the screening installation 10 to a discharge point 24 located behind the rear crawler track 6. In the process, an advantageous mixing effect takes place which is still enhanced by the vibrating screen of the screening installation 10 over which the material is guided with the aid of a cover plate. The formation material discharged upon the exposed earth formation 19 is graded and consolidated by means of a consolidating device 25, and thus a rehabilitation layer 26 is formed.

(9) In further sequence, gravel 27 can be discharged upon this rehabilitation layer 26, said gravel having been separated out and intermediately stored during the ballast cleaning process as still-usable spoil, and which is now graded to form a protection layer 28, as can be seen in FIG. 2 all the way on the right. Likewise, the ballast 9 picked up by the clearing chain 8 and cleaned in the screening installation 10 canafter the intermediate storagebe discharged, as desired, upon the rehabilitation layer 26 for creating a ballast bed.

(10) In addition, there is also the possibility to place a foil 29 on the rehabilitation layer 26 prior to the discharging of gravel 27.