ES2587272T3 - Railroad support system - Google Patents

Abstract

A method for stabilizing a railway track (10) comprising: Inserting an elongated support (20) having a generally hollow interior in the ground in the vicinity of an existing railroad track (10) in situ, the support (20) is inserted at a depth such that the entire support (20) is below the ground surface thus leaving a gap (28) between the support and the ground surface; inserting a cementitious material into the hollow interior of the support (20) characterized in that the ballast material (18) is inserted in the vacuum (28) between the support (20) and the ground surface; the support (20) is between 2 and 8 meters in length and is inserted into the ground in a generally vertical orientation to the depth such that the support (20) drills through and substantially covers the depth of the region (34) of the subgrade once inserted.

Description

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DESCRIPTION

Railroad support system

The present invention relates to a method to support or stabilize a railway, and more particularly, to a system to stabilize the existing road, for example to remedy or control land settlement problems.

The railroad conventionally comprises a pair of spaced rails laid on sleepers that support the passage of the rail vehicle over the rails. The sleepers are typically laid sideways in relation to the rails and supported on ballast, such as ground stone or the like.

While the combination of subgrade, ballast and sleeper layer materials is generally sufficient to dissipate the compressive force of a rail vehicle passing over it, it is a recognized problem that the nature of the underlying soil's conformation can adversely affect the stability and / or the longevity of the road. For example, if the underlying soil comprises the ace! called "wet bed", for example, which may contain a proportion of peat, it is possible that the ground below the road can contract and thus originate the broth or subsidence of the road.

The above scenario represents a specific example, by means of which the underlying soil can cause deterioration of the road geometry, and it will be appreciated by the skilled person that there are other examples in which the subgrant typically comprised of fine-grained soil, clayey or silty, below the railroad track may be insufficient to support the passage of rail vehicles during the time due to ground settlement, compression and other phenomena. Such effects can be attributed to, for example, moisture-density-resistance ratios and / or the corresponding soil properties such as bearing capacity or compressibility.

The deterioration of the road to a relatively small degree can lead to speed restrictions that are put in place. Under more pronounced conditions, road deterioration can lead to serious safety risks.

The problems described above are more prevalent as the train speed capacity increases. In particular, an increase in the speed of ferrous vehicles can lead to a faster deterioration of the road. Even in relatively minor cases of road dislocation, significant investments made to supply improved trains can be denied are capable of higher speeds due to the need to impose speed restrictions on portions of the rail network.

Conventional methods to reestablish the road have required the complete removal or renovation of the existing road, including ballast reposition and realignment of the road over the ballast. Some conventional methods include adding an adhesive material to the ballast in hopes of preventing future deterioration. Such processes are costly and time-consuming and can result in significant downtime on the road, which can additionally cause associated costs and disruption to the operators of ferrous vehicles. Additionally, even if attempts are made to treat the shallow subgrade or improve the performance of the ballast layer, the replacement of the track may be subject to additional ground or ground movement below it, so that it may be required in the future reestablish the road additionally.

Such a method is described in document NL 8 801 026 where support components are formed by inserting a hollow cylindrical body (3) into the ground and pouring a hardened mixture. The body is removed, allowing the mixture to consolidate.

It is an objective of the present invention to provide a method for stabilizing existing railways while at least some of the above problems are mitigated. It can be considered as an alternative or additional objective of the invention to provide a system for stabilizing existing railways on site.

JP 2006 037413 describes a method to improve the terrain that can be used with the existing road in situ. The bars 22 are driven between the sleepers 4 of the railroad track through the ballast layer 6 to improve the ground area, and a beam 16 which is then installed between the bars 22 and the sleepers 4 to support the track.

In accordance with the present invention, a method for stabilizing the railway is provided as described in the attached revindication 1. The method comprises inserting an elongated hollow support in the ground in the vicinity of the railway track, the support being inserted at a depth such that the complete support is below the surface of the ground thus leaving a gap between the support and a surface

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of the land; insert a first cementitious material into the hollow interior of the support; and insert a second aggregate material into the gap between the support and the ground surface.

The method can be advantageously carried out in situ for an existing railway track. Accordingly, the land surface can constitute the level of an existing ballast layer, to which the second aggregate material can be increased. The method can be repeated or duplicated along the length of the railway. Any, or any combination of the methods can be repeated concurrently or sequentially at different sites along the length of the path.

The cementitious material is typically inserted into the support in situ.

The present invention is broadly applicable to existing railways, which have the advantage that the method can be carried out in areas, such as, for example, the approach to train stations, where it is impractical to carry out road restoration methods. Conventionals that require a new supply of ballast. Additionally, the reestabilization of a length of the track can be carried out in stages (that is, inserting one or a small number of supports at the same time) without interrupting the use of the track between those stages.

The terrain may comprise a relatively soft or humid subgrade region and the method comprises inserting the support into said region. The support can be inserted in such a way that it extends through said subgrade region. The support is between 2m and 8m long, which is of an order of magnitude similar to the depth of the subgrade region.

In one embodiment, the method can be performed in a region in which the ground below the subgrade is typically harder than the softer subgrade region.

Accordingly, the support can allow load communication from the ground surface to the hardest region immediately below the subgrade. That is, the support may allow the load on the softer subgrade to be reduced during the passage of rail vehicles on it, or it may also allow the soft subgrade to be at least partially derived or short-circuited in capacity to withstand load.

According to a preferred embodiment, the support is inserted into the ground at a site between adjacent sleepers of the railway. Two brackets can be inserted in spaces spaced in the space between adjacent sleepers. The two supports can be spaced laterally with respect to the direction of the track. One or more supports can be inserted in the field between successive pairs of adjacent sleepers along the length of the track to be supported. The supports can be inserted between successive pairs of sleepers in a regular repetitive pattern along the length of the track to be supported. For example, brackets can be inserted between pairs of alternative sleepers.

The, or each support, can be inserted into the ground at a site between the opposite rails of the railway. Additionally or alternatively, one or more supports can be inserted into the ground immediately outside or adjacent to the rails, but typically between adjacent sleepers.

The support can comprise a generally tubular body that can be closed at one end.

The support can have a first end or front end, which is to be inserted into the ground at a greater depth than the second end or rear end. The first end can be closed. The second end is typically open or has an opening in it to allow the insertion of cementitious material into the hollow interior of the support.

The second end or rear end may comprise a flange formation head. The formation can have a width or a larger diameter than the rest of the support. The formation may comprise a circumferential end wall. The formation can be attached to the support during the method of the invention. For example, the support can be propelled to the ground at a first depth such that the second end is above the surface of the terrain, at which point the formation can be attached to the support before driving the deeper support in the land. A driving force can be applied to the support via the formation, for example by means of a correspondingly shaped or sized drive tube.

The support can be a battery.

One or more openings can be supplied in the holder. The support can be overfilled with cementitious material such that it passes through one or more openings in the ground. Can be supplied

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one or more openings in a wall (eg side wall) of the support. In use, a portion of the cementitious material inserted into the support can be filtered through one or more openings. This escaped portion of cementitious material can enter or penetrate the surrounding subgrade or substratum and thereby improve its stabilization.

The length of the support can typically be between 2.5 and 7 meters or 3 and 6 meters.

The aggregate material may comprise a coarse aggregate. The aggregate material may comprise ballast. The aggregate may be loose. The average grain size of the aggregate is typically significantly greater than that of the cementitious material.

According to one embodiment, the support can be overfilled with cementitious material such that the volume of cementitious material rests above the highest end of the support with the vacuum. This can form a cementitious lid on the support. When the aggregate material is inserted into the vacuum, it may advantageously enter the cementitious material in the vacuum in such a way that it forms a region in which both the aggregate and the cementitious material are present. Such intermediate region may be located in a lower region of the vacuum, this between the support and the higher ballast region once completed.

The cementitious material can be poured into the support using a tube, such as the ace! called Tremie tube.

The vacuum can be filled with the added material via a hollow or tubular member. The aggregate may be allowed to fill the void during retraction of the hollow member. The vacuum can be re-filled with aggregate. A drive tube can be used to drive the support towards the ground. The added material can be inserted into the vacuum via the hollow delivery tube.

In accordance with a further aspect of the invention, a railroad support system is provided in accordance with claim 14, which comprises a plurality of submerged supports in a generally vertical orientation below the ground level in the vicinity of the track. ferrea, each support has a solidified cementitious material in it and where the region between the uppermost end of the support and the level of the land on which the railway track is located is substantially filled with aggregate.

Any of the optional features defined in relation to the structure formed by the method of the first aspect, or other components or materials used in said method, can also be applied to the system of the second aspect.

The terms "via ferrea" and "sleeper" in British English, as used herein, may be considered interchangeable with the terms "railway" and "naughty" as used, for example, in American English.

The practicable embodiments of the invention are described in further detail below with reference to the accompanying drawings, in which;

Figure 1 shows a side view of a conventional railway section to be stabilized in accordance with the present invention;

Figure 2 shows a sectional view through a support and an associated railway track during stabilization according to an embodiment of the invention;

Figure 3 shows a front view of a plurality of the supports shown in Figure 2 located in relation to the railway;

Figure 4 shows a sectional view of a railway support system according to an embodiment of the invention; Y,

Figure 5 shows a plan view of a section of a railway track that includes the location of the supports for stabilization of the track in accordance with a further embodiment of the invention.

The present invention derives from a basic concept that it is possible to adequately stabilize a section of the railway track to the appearance of the deterioration of the track due to poor subgrade support when stacking in the vicinity of the railway track. This can be achieved for example in the window of opportunity when the deterioration of the road has been detected but while the road is still safe for use. Such a window of opportunity can occur, for example, when the speed restriction is placed on a section of the road to avoid further degradation of the road.

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Returning first to Figure 1 and 3, there are shown portions of the conventional rail track 10 comprising a pair of spaced rails 12 supported by sleepers 14 arranged laterally that keep the rails in the desired spacing or caliber. The elastic insurers 16, or variants thereof, are used to attach a rail 12 to each sleeper 14. Typically two insurers are provided per sleeper, one on each side of the rail, as can be seen in Figure 3. The rails, Sleepers and insurers are all of conventional design and materials and do not need to be altered to accommodate the present invention.

Sleepers 14 are laid and supported by a bed of ballast 18. The depth and conformation of the ballast may vary from site to site, but typically comprises fragmented, ground or other coarse stone or gravel. A conventional track arrangement comprises both ballast and sub-ballast layers, with the previous upper ballast layer comprising generally larger pieces, while the sub-ballast layer typically comprises a smaller grain size particulate material that supports the upper ballast layer.

The process carried out in accordance with an embodiment of the invention is described below with reference to the structure of the conventional route of Figure 1.

First a volume of ballast 18 is removed from between adjacent sleepers 14. A stack 20, typically formed of steel or other conventional stacking material, is oriented vertically above the space between adjacent sleepers 14 and rails 12 as shown in Figure 1. The stack 20 is generally tubular in shape and has an end. 21 closed and an opposite open end 22. A diameter stack between 100 and 250 mm, or, more specifically between 120 and 160 mm, may be suitable. In the present embodiment, a 140 mm stack was selected.

In alternative embodiments, the stack may have an open end and may be supplied with a reinforcing or cutting member, such as the ace! called a cutting shoe, which can take the form of a collar member arranged for annexation around the open end of the stack.

The battery length may be an acceptable length for the given pile diameter and the resistance requirements in use and may be between, for example, 2 m and 8 m in length depending on the subgrade at the installation site. In the present example a stack length between 3 and 6 m was used. However, other use cases of the invention will typically involve geotechnical studies and / or structural design calculations to determine the proper length of the stack or the depth of insertion, which may be outside the range suggested above.

The stack 20 is driven on the ground between sleepers 14 in a generally vertical direction using conventional stacking machinery such that the closed end 21 enters the ground first. However, in a location in which the road is curved in the plane and / or protected or angled in some other way relative to the horizontal, the battery can be inserted in the ground at an angle to accommodate such characteristics. The angle of insertion may be substantially perpendicular to the angle of the sleepers, or obliquely angled in relation to these as necessary. The stack is initially driven to the ground at a depth such that the portion of the stack toward the upper end 22 remains exposed above the ground. At this point a flange member 24 is attached, in situ, to the open end 22 of the stack.

The flange member 24 is shown in Figure 4 and comprises a generally disk-shaped member having a central opening 25 therein. The opening 25 is substantially aligned with the longitudinal axis of the stack such that the flange member 24 rests against the open end of the stack. The flange member 24 may have one or more location formations that are arranged for insertion at the end of the stack to facilitate correct placement and subsequently fix the flange member to the stack. Once the flange member 24 is rigidly fixed in this manner, it provides a head formation at the end 22 of the stack.

The stack 20 is further driven into the ground using a drive tube 26 as shown in Figure 2. A drive force is applied to the stack 20 via the tube 26. The tube 26 can also be vibrated in order to additionally assist the stacking process, particularly as the pile passes through the ballast. The stack can subsequently be pushed as it progresses through the subgrade material.

The delivery tube is larger in diameter than that of the battery 20 but less than or equal to the outside diameter of the head formation 24. This causes the formation of a vacuum 28 above the stack 20 to the extent that it is inserted into the ground. The vacuum 28 is of a diameter width that is greater than that of the stack 20 and typically substantially equal to that of the width / diameter of the tube 26 and / or flange 24.

The stack punches the subgrade material and is driven until the end 22 achieves a predetermined depth below the ground surface. The predetermined depth, shown as dimension "Y" in Figure 2 can be, for example, 1 m. Additionally or alternatively, the predetermined depth may be such that the open (upper) end 22 of the stack, and the associated flange 24 are approximately at a lower level of the ballast or subbalast layer. Additionally or alternatively, the stack can be driven in such a way that its lower end (closed) 21 comes into contact with the bedrock or the layer of additional material immediately below the subgrade material. It will be appreciated that the exact depth will vary from location to location depending on the terrain conditions and the length of the battery used. However, the end of the top pile will typically achieve a depth of between 0.5 and 3 m below ground level.

The depth to which the battery is driven can be determined based on the length of the drive tube that is above ground level. Typically, the delivery tube is long enough so that at least a portion of it is exposed above ground level when the battery reaches its final resting position / depth.

15 The wider width of the flange 24 relative to the body of the stack is advantageous since it drags finer, typically particulate, ballast material with it during the insertion of the stack. This is described in Figure 2 in 29. This "cradle" of ballast material can help stabilize the battery within the subgrade and can also serve to promote the transmission of charge to the battery via the ballast once it is Ferrea is back in service.

20 The final resting position of the stack is shown in Figures 2 and 4. Here it can be seen that the open end 22 of the stack generally rests in the region of interface 30 between the existing ballast (32) (or sub-ballast) and the subgrade 34. Also the bottom, closed end 21 of the stack rests approximately in the region of the interface 36 between the subgrade 34 and the additional material 38, such as a bed of rocks, or a layer of subgrade material more deep, which is typically harder / stronger than the subgrade 25 34. The material 34 of the subgrade, through which the battery is inserted can constitute a subfloor or a layer

Substrate

The stack is then filled with a concrete or resin material via the open end 22. This is achieved by first retracting / raising the drive tube a small distance, such as about 100-300 mm, above the shoulder 24. A Tremie tube is inserted below the hollow drive tube 26 and the resin is poured into the stack 20 through the opening 25 in the flange.

A water-cement ratio of approximately 0.45 is used, although an alternative proportion generally in the range 0.4-0.5 may be adequate.

The battery is overfilled with resin. That is, the resin is poured to the level where the resin is above the level of the flange 24 such that the resin fills, or at least partially, fills the space left between the end of the delivery tube and the flange. In this embodiment the resin is filled to the level of the lower end of the impulse tube. This resin overfill supplies an "end cap" 27 comprising cementitious material immediately above the head of the stack. Also, since the retraction of the impulse tube 26 may cause the partial collapse of the ballast material above the vacuum 28, the end cap region typically will comprise a mixture of ballast and resin. The intermediate region 40 is advantageous for transferring the load from the ballast to the stack 20 once it is consolidated (ie when the railway is in service)

The resin can also, at least partially, penetrate the cradle 29, further stabilizing the stack.

As part of the filling process, the resin is typically poured at the desired level and then allowed to settle / stabilize for a short period of time, such as one to a few minutes. The resin level 45 can then be brought to the top if it falls into this schedule.

The vacuum 28 is then filled with ballast. This is achieved by re-filling, so that the vacuum is filled by pouring the ballast material through the tube, while the tube is being retracted. Depending on the conformation of the existing ballast, a thinner subbalast material can be inserted first followed by a thicker ballast material to resemble the surrounding ballast structure. The filling material 50 can thus! comprise a ballast and a granular mixture.

The ballast filler material can generally be distinguished from the resin material in that the ballast is generally loose / dry and the grain size is typically an order of magnitude or greater than that of the wet resin material.

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Once the tube 26 has retracted, the ballast 18 between the sleepers 14 can be filled to the desired level, or with the existing ballast (previously removed) or other fresh.

The resin is then consolidated forming a strong support for the railway via the problematic material of the subgrade. It can also be seen that the resulting end cap region 27 is substantially formed at the interface 30 between the existing ballast and the subgrade layers 34.

Figure 2 shows the locations of the batteries in relation to the existing rails 12 and the sleepers 14. The batteries are inserted in pairs, each battery in the pair being spaced from the other by a longitudinal axis 40 of the track . In particular, the batteries are symmetrically located on each side of the axis 40. Each battery can be spaced laterally from the axis such that each battery is closer to the rail 12 than to the axis 40. The center of each battery can be spaced from the corresponding rail at about 250-300 mm, typically about 275 mm.

Each stack is preferably equidistant between adjacent sleepers 24.

The batteries are inserted between each third pair of adjacent sleepers 14. However, in particularly problematic areas it is possible that the batteries can be inserted between each pair of sleepers. On the contrary, batteries can be inserted between pairs of sleepers less frequently in less problematic areas. A repeated pattern of "stacked" and "unstacked" pairs of sleepers can be created along the length of the track. Additional repetitive patterns of the batteries can be used, for example in which pairs of batteries arranged as described above are spaced apart by an intermediate battery.

Returning now to Figure 5, a sequence in which batteries can be inserted is shown. The batteries 20 are numbered from 1 to 8 to show the order in which they were inserted in the field. In this way a longitudinal row (with respect to the axis 40 of the track) of the batteries 20 is inserted before insertion of the adjacent row of batteries. Each battery can be installed and filled before inserting the next battery in the sequence. Typically ballast retrollenado will also take place before moving to the next stack. However, different sequences and insertion orders are possible depending on the available machinery and in the interest of achieving installation efficiency as long as this does not cause a detriment to the support system.

Figure 4 shows a schematic section through the stack and the surrounding terrain after the support system has been installed. In use, to the extent that a railway vehicle passes over track 12 above the pile and the temporarily applied load is communicated via sleepers and ballast through region 27 of end cap and the stack itself 20 to terrain 38 firmer below. The support system therefore serves to reduce the load applied to the subgrade in use and so! prevents any further deterioration or deterioration of the subgrade.

The deformation of the subgrade has been found to be the primary factor to cause deterioration of the geometry of the existing road and so on! The present invention effectively mitigates this problem in its root cause and in a way that does not cause a significant disruption of the road. When placing the batteries between the sleepers it is considered that it is particularly beneficial to support the load of the railway vehicle that passes over it. However, it is possible in other embodiments that the stack can be taken at adjacent sites instead of between the track and / or the sleepers. In one embodiment, the support structure left in place by the installation process described above improves the module of the track and / or the rigidity of the track.

Although the above-described embodiments of the invention relate to the use of a hollow tubular stack, it will be appreciated that other hollow support profiles can be used which leave at least a partial vacuum behind the front end of the support after insertion into the ground. . Other hollow supports may include for example box section batteries. Alternatively, batteries that are open-sided in the section but that define a partially enclosed interior space, such as the section and (for example, the so-called Universal Beam or Universal Column), batteries in section H or section C (Channel ) can be used for similar effect. As with the closed end of the tubular stack, such alternative stack forms may have an end or plate formation to dislodge the subsoil after insertion in order to leave a void along the length of the inserted stack, which It can be subsequently filled with resin. Such internal or internal void will be joined by the stack or walls.

All such variants of the invention will typically be of an extruded construction, such that the section profile is substantially constant along the length of the stack, except for any of the end formations. Also, all such variants will be linked or at least partially linked to an internal space between the opposite wall portions of the stack.

In a further development of the invention, the stack can be supplied with openings through one or more walls thereof such as side walls, net or flange walls. Thus, when the resin is poured into the stack, a volume of resin will flow through the gaps and into the surrounding substratum. That resin will penetrate the substratum to a degree and thus serve to stabilize the soil that surrounds the pile immediately. This can also serve to improve the bond between the stack and the subgrade. The openings in the stack will typically open in a substantially lateral direction relative to the longitudinal axis of the stack. The openings are sized to allow the escape of only a fraction of the resin, such as 20% or less. When a battery having such openings is filled, the battery will typically overfill initially, followed by an extended duration wait to allow the resin to pass through said openings in the surrounding subfloor, before the resin reaches the top. at the desired level

Claims (15)

5 10 fifteen twenty 25 30 35 40 Four. Five Claims 1. A method for stabilizing a railroad track (10) comprising: Insert an elongated support (20) having a generally hollow interior in the ground in the vicinity of a railroad track (10) existing in situ, the support (20) is inserted at a depth such that the entire support (20) is per below the ground surface thus leaving a void (28) between the support and the ground surface; insert a cementitious material into the hollow interior of the support (20) characterized in that the ballast material (18) is inserted into the vacuum (28) between the support (20) and the ground surface; the support (20) is between 2 and 8 meters in length and is inserted into the ground in a generally vertical orientation to the depth such that the support (20) drills through and substantially covers the depth of the region (34) of the subgrade once inserted. 2. The method of claim 1, wherein the support (20) is inserted into the ground at a site in a longitudinal direction of the track (10) between the locations of the existing sleepers (14) of the rail track (10) ) and / or between the existing rails (12) of the railway (10) 3. The method of any preceding claim, wherein the support (20) is closed at a first end (21) and opened at a second end (22), the first end (21) is inserted into the ground in front of the second extreme (22). 4. The method of any preceding claim, wherein the support (20) is supplied with a projecting flange member (24) outwardly in the vicinity of the rear or upper end (22) thereof during insertion. 5. The method of claim 4, wherein the support (20) is driven to the ground by a drive member (26) that applies a driving force to the support (20) via a flange member (24) . 6. The method of any preceding claim wherein the support (20) is overfilled with a cementitious material in order to form a bulb (27) of cementitious material above the upper end of the support (20). 7. The method of claim 6, which depends on claim 5, wherein the drive member (26) is partially retracted such that the lower end of the drive member (26) is spaced from an upper end of the support (20) immediately below the ground surface by a space and cementitious material is poured in order to at least partially fill said space. 8. The method of claim 7, wherein the cementitious material in said space hardens to form a head formation (27) at the upper support end (20). 9. The method of claim 6 or 7, wherein the amount of ballast material (18) is also present in said space. 10. The method of any preceding claim, wherein the support (20) is driven into the ground using a hollow drive member (26) and the cementitious material and / or ballast material (18) is inserted into the vacuum (28 ) via the hollow interior of the drive member (26). 11. The method of any preceding claim, wherein one or more openings are provided in the support (20), preferably in a side wall of the support (20) as! as well as at one end (21) thereof, a portion of the cementitious material inserted in the support (20) and it is allowed to filter through one or more openings. 12. The method of any preceding claim, wherein two of said supports (20) are inserted into the ground at laterally spaced sites with respect to the direction of the track (10) in the space between adjacent sleepers (14). 13. The method of any preceding claim, wherein one or more of said supports (20) is inserted into the ground between successive pairs of adjacent sleepers (14). 14. A railway support system, comprising a plurality of supports (20) submerged, in use, in a generally vertical orientation below the ground level of the neighborhood of an existing railway track (10), each support has a higher end (22) with a head formation (27) comprising solidified cementitious material thereon; characterized in that each support (20) comprises a hollow profile 5 closed at one end (21) and having a solidified cementitious material in it, the support (20) is between 2 and 8 meters in length and is located at a depth such that they cover a region (34) of soil of the Subgrade and the system also includes material (18) added between the uppermost end of the support (20) and the level of the land on which the railway track (10) is located. 15. A railroad support system according to claim 14, wherein each support (20) has a flange portion (24) and its upper end and the head formation (27) comprises cementitious material solidified on said flange portion (24).