Patent Application
20100320279
This present invention relates to a method for the installation of slab tracks in twin tube tunnels, that contributes essential characteristics of novelty and appreciable advantages compared to the other known and used methods used for the same purposes in the current state of the art.
More specifically, the invention proposes the development of a method defined by a succession of consecutive phases or stages for the installation of slab tracks on the inside of a tunnel, each one of these phases being designed in an optimised manner in so far as their construction, execution and performance characteristics, with the introduction of adapted mini trains that move along an auxiliary side track which goes along the areas in which work is being carried out without directly interfering with them.
The field of application of the invention is the industrial sector involved in the installation of railways in general, and concrete slab tracks in particular.
As is well known by skilled persons in this field, slab tracks, or tracks on a slab of concrete, are a type of railway track that sits on concrete or asphalt beds, these materials replacing the conventional ballast. The criteria for their construction are much more demanding than those of traditional track, as they require greater precision in so far as refers to the levelling, alignment and track width, as any subsequent correction of possible mistakes is very expensive. Along these lines, it is particularly important to provide effective drainage so as to eliminate possible future maintenance problems, as in traditional tracks it is the ballast that guarantees this drainage function.
Slab tracks have the disadvantage compared to traditional tracks, that the construction cost is higher than for the latter, but on the other hand, they have a series of significant advantages compared to traditional tracks, from various points of view: On one hand, they guarantee the correct positioning of each one of the elements that make up the track, such as the rails and sleepers, keeping the geometric parameters unchanged over time, and on the other hand, require less maintenance work than traditional tracks, with a reduction which according to some estimates is in the order of some 20% less, which thus allows the intervention times to be reduced and, consequently, increases the operating availability of the infrastructure.
In addition, slab tracks also have some other positive aspects amongst which the following can be mentioned as examples: greater safety and reliability of their performance and repair in case of derailments, which in turn are less probable owing to the fact that slab tracks have two defences: One active, that reduces the formation of transversal defects, which translates into greater train stability, and another that is passive, based on its robustness, which makes it more solid from a structural point of view.
In accordance with the known methods of construction, the slab track can either have embedded rails, that is, the rail is introduced onto the inside of a channel made in the concrete slab, in such a way that the rail is supported along its entire length with the resulting reduction of stress and a better distribution of the loads, both static and dynamic, or with the rail assembled on sleepers. In whichever case, the parts that can be highlighted on a slab track are as follows:
The above is a summarised exposition of the differing components that are used in the construction of a slab track, together with some performance characteristics of same.
Given the high number of advantages gained from the installation of slab tracks compared to conventional tracks on ballast, it is desirable to be able to have the methods available that allow the assembly to be used in those cases in which its use is advisable, or which are suitable for whatever circumstance. This present invention has been developed taking the above need into consideration, and to that end is aimed at providing an installation method for slab tracks on the inside of tunnels that improves the traditional methods, where the space available is much more limited than on open land, and because of this a process sequence has been developed by means of which solutions are provided for the differing construction phases. This sequence of process stages constitutes the essence of the invention method, and is going to be described in greater detail below:
As has been mentioned above, the detailed description of the slab track installation method is going to be described below with the particular application of the case of a twin tube tunnel, this means, a tunnel made up of two separate tubes with each one of them having a single track. The explanation is made on the basis of one of the tubes, it being identical for the case of the second tube.
According to the method developed for the invention, the installation of the slab track includes the following stages:
1. Formation of the construction section
2. Design and construction of the railway yards
3. Assembly of auxiliary track in the maintenance lane
4. Stocking of the sleepers on the evacuation platform
5. construction of the foundation base
6. Assembly of the slab track
7. Slab track transitions—ballast
8. Provision of long bars and welding
Next the characteristics that distinguish each one of the different stages are explained.
The construction section has been designed in such a way that it is constructed with two platforms, one on each side, between which the foundation base is located as well as the slab track. The free horizontal width is much reduced, thus preventing the simultaneous movement of lorries and other mechanical devices, which means lengthy cycles and therefore has a negative influence on final performance. For this reason, the invention has envisaged the use of mini-trains adapted to the production needs associated to each one of the process phases, and capable of moving along an auxiliary track, built for this purpose, simultaneous to the carrying out of each one of the cited phases, described below. The construction sections are apt to have variations and can include a narrow maintenance lane, a wide maintenance lane, or a very wide conventional platform, in accordance with the needs of the differing places along the tunnel.
In accordance with a second stage of the invention method, a place is specified for the construction of a railway yard, this being a basic characteristic for the logistical development of the works to be carried out. The railway yard has a number of tracks that is sufficient for the fulfillment of the activities of loading and unloading materials, likewise control centre and workshops.
As stated above, the assembly of an auxiliary track to provide services in regard to the differing activities that are being carried out, extended beyond the areas in which work is being carried out, can be undertaken along the maintenance lane simultaneous to the construction of the railway yard described in the previous section. Because of this, the drilling of the platform and the placement of the pins is carried out in the places in which later the retention bolts of the auxiliary track will be placed. In addition, at certain pre-determined distances (e.g. every 3.5 km in the case of a preferred practical embodiment in accordance with the invention), a siding will be made for the purpose of marshalling the movements and forward point of the different activities that are being carried out in an overlapping manner. The rails for the construction of the railway lines can be transported up to the assembly point by means of trailer-cranes or with mini trains, depending on the situation of the works, moveable along the stated auxiliary line.
This activity precedes the laying of the concrete of the foundation base transported by the concrete mini train, which requires more movements than the sleeper mini train, as the latter transports a limited number of sleepers on each trip. The operation consists of the sleeper mini train being stationed in front of the concrete mini train, and with the help of mini back loader type of machine, the sleepers are stockpiled and are distributed in batches, for their subsequent use in the assembly phase of the slab laying.
After this, the pouring of the concrete and its spreading with vibrating bars and vibrators is proceeded with by means of the concrete mini train so as to achieve a uniform and exact level that complies with the standards that are applicable to the case.
It is necessary to have a predetermined length of the auxiliary track for the carrying out of this stage, in accordance with the final performance required and provided that the logistical system so permits.
The stage comprises several phases of activity, which are as follows:
6.1: Distribution of the sleepers in the foundation base
6.2: Reinforcing of the track and 1st levelling
6.3: 2nd levelling
6.4: Concreting
6.5: Advance of the assembly line or track layout
The operation for the distribution of the sleepers consists of carrying out the consecutive distribution of the sleepers, in an equidistant manner, along the tunnel and at a distance as stated in the project. The process includes locating the mark points on the platform, and to carry out the setting out of an axis that can be used for the correct alignment of the sleepers, meanwhile a mini-back loader, provided with a carrying platform, carries out the distribution of the sleepers, for example 4 by 4, that have previously been distributed along the platform.
Next, with the sleepers positioned on the foundation base, the reinforcing operation of the track and the 1st levelling is carried out. To do this, the placement of the track proceeds with the help of the mini-train which moves along the length of the auxiliary track, with a capacity for a specified number of rails depending on the length of same, and fitted with a number of synchronised gantries, for example, 8 gantries in a preferred embodiment. After this, the square setting of the sleepers is proceeded with, subsequently fastening the rails, and fixing the sleepers with an adequate predetermined torque so as to ensure the contact of the rail with the sleepers, but without reaching values that would put the integrity of the pins in jeopardy.
After this, the placement of levelling members and the hydraulic aligners-levellers is proceeded with and the positioning is carried out along the stretches of track at predetermined lengths, adjusting the marking points, leaving the track held down with the screws of the levelling tackle.
This levelling and alignment constitutes the adjustment and checking process for the track handed over by the assembly team. It is the waiting time for the concreting of same.
With the topographical equipment, for example digital topographical equipment, which progressively moves along the railway track the final adjustment is made. The equipment includes an automated tachymeter with a measuring carriage that has a computer by means of which the geometry of the track is analysed in real time. Tools such as ratchet braces and alignment spanners are used to reposition the track.
Once having finished the already described levelling operations, the following phase of the process consists of the concreting of the track, carried out from the position of the auxiliary track, in order to do this in the first place to duly protect both the track and equally the fixings; next to carry out the pouring of the concrete by pipe or by distribution and vibration, and finally, the trowelling and cleaning operations of the sleepers and the fixings.
After the concrete poured in the previous phase has gone off, the dismantling of the levelling tackle is carried out and the unhitching of the auxiliary track, for the purpose of loading it on the mini-train which has to transport it to the distribution of sleepers phase, once again starting the cycle.
Depending on the variation of the rigidity required, thus will be the length and the types of sleepers and the fixings to be used.
Along general lines, the connection of the track on ballast slabs is carried out by means of the construction of a small trough slab, for example of the length of around some 10 metres, that confines the ballast and alters the thickness depending on some predetermined values, for example, 20 to 35 cms under the sleeper. Prior to the trough, in the area of the concreted track, double fix sleepers are placed, just the same as with the trough, so as to place two fastening members.
The long bars can have variable lengths from 60 to 90 metres, or others depending on the limitations for each particular application. They are normally transported along the railway track by the mini-train, with two possibilities for unloading: Mini train with side unloading, or equally with conventional unloading mini train moving in reverse.
In so far as the welding, electric welding is preferred, although other suitable welding techniques are acceptable.
As will be understood, the installation process of slab tracks for use in railway tunnels that has been described above, optimises the different construction phases of the process, and allows for a considerable increase in the performance of the method up to production values that are very much higher than those for the normal methods in the current state of the art.
It is not considered necessary to make the contents of this present description more extensive in order for a skilled person in this field to be able understand its scope and the advantages that arise from same, likewise how to carry out the practical embodiment of its aim.
In spite of the above, and given that the description made corresponds solely to one example of a preferred embodiment, it will be understood that within the essence of said embodiment there may be introduced multiple modifications and variations of detail, likewise comprised within the scope of the invention, and that will be able to affect characteristics related to different phases of the process provided that it does not alter any of the basic principles of the invention, in accordance with that which has already been described and in accordance with that which is defined in the claims that follow.
| Number | Date | Country | Kind |
|---|---|---|---|
| P200901421 | Jun 2009 | ES | national |
