RU2476634C2 - Mechanised method to lay geosynthetic materials (geotextile and volume grating) into road structure - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: geomaterials - geotextile and volume grating are stretched onto an area of an earth bed prepared for development with a traction force of a special road machine. Geomaterials are taken from those available on the machine or on upkeep device platforms coupled with it. Besides, the volume grating is installed above geotextile and transformed into a cellular volume structure, which at the start section is fixed to soil with several time anchor stands. Then it is immediately filled, levelled and compacted to avoid displacement with a material specified by the project (sand, sand and gravel mixture, crushed stone, etc.) from the one available on the machine or a hopper coupled with it.

EFFECT: improved manufacturability, reduced time for performance of works, reduced manual labour of roadworkers.

2 cl, 2 dwg

Description

The invention relates to the field of road construction, in particular to methods for improving the operational characteristics of road structures and can be used in the construction of roads and railways or other similar structures requiring special means for hardening pavement.

Known and widely used in the world practice of road construction is a method of hardening pavement by introducing into one of its layers geosynthetic materials, such as geotextiles and voluminous geogrids. The specified method is shown on the website www.prs-med.com. described, for example, in the “Guide to the construction of airfield bases and pavement with reinforcing layers of geosynthetic materials. ARDS 32-12-08 Ministry of Defense of the Russian Federation. M., 2008 ”, in the document“ Recommendations on the use of geosynthetics LLC “Hexa-nonwoven materials” in road construction (woven geosynthetics, volumetric geogrids), Yekaterinburg-2008 ”, in the draft management document of JSC“ Russian Railways ”“ Experienced the technological process of laying the NEOVEB volumetric geogrid in local areas. "

The mentioned methods are generally identical and can be taken as the closest analogue. The implementation of the method is carried out by sequentially performing the following operations:

- preparation of the subgrade (planning, compaction, drainage device, etc.) by road machines;

- distribution of sections of the volumetric geogrid and geotextile rolls (manually);

- rolling the sheets of rolled geotextiles lapped manually, or with the fixture of a road machine (panels can be sewn together);

- manually stretching over the geotextile sections of the volumetric geogrid to the width specified by the project to form the volumetric honeycomb structure, fixing the geotextile and geogrid on the ground with temporary anchor racks (the geogrid sections are manually fastened to each other with metal staples using a stapler or in another way);

- filling with road machines the geogrid cells with bulk materials (sand, gravel, gravel, etc. - in accordance with the project);

- extraction of temporary anchor racks (manually);

- planning and compaction of road-borne material by road machines, application of surface asphalt concrete or other coatings by road machines, or laying of a crushed stone ballast prism of a railway track.

The disadvantage of the closest analogue is the low efficiency, the need for large amounts of manual labor for traveling workers engaged in stretching and securing geomaterials, installing and removing temporary anchor racks, and in case of repairing a railway track, in addition, the need to remove and reinstall the rail and tie sections. This method also requires a large expenditure of technological time and, accordingly, long-term closure of the facility for repair.

The objective of the proposed technical solution is the mechanization of the method of laying geotextiles and geogrids in the appropriate layer of the road structure, which will significantly reduce the number of workers required to complete the work, reduce the time it takes to stretch, fix and fill geosynthetics. When repairing a railroad track - the performance of work without removing the rail-sleeper.

A mechanized method of laying geosynthetics in the road structure is proposed, including the following common operations for the closest analogue and the claimed technical solution:

- preparation of the subgrade by road machines;

- extraction of temporary anchor racks (manually);

- laying by road machines of a surface coating, (for example, asphalt concrete), or laying of crushed stone ballast prism of a railway track.

In contrast to the closest analogue in the claimed method:

- a number of technological operations are carried out by a specialized road machine (hereinafter referred to as the Stacker), adapted to the place of work: for example, a road, an airfield, a railway bed-truck chassis, a railway-track railway machine);

- the geogrid section of the projected length is located on a special device (drum, rack) of the Stacker, or on an associated platform;

- geotextile rolls are also located on the Stacker or on a platform connected to it;

- the geogrid is installed on top of the geotextile being unwound from a roll and is stretched due to the impact on the extreme geogrid ribbons and the geogrid of the working bodies (for example, plates, boxes, disks, sprockets) of the corresponding Stacker mechanism;

- the geotextile is removed from the roll, and the bulk geogrid from a special device is produced by the pulling force developed by the moving Stacker, for which geotextiles and geogrid are attached to the subgrade with several temporary anchor posts;

- filling the cells of the stretched geogrid with bulk material removed from the hopper located on the Stacker, or on the platform connected to it, occurs almost immediately after their formation when stretching, which allows the use of temporary anchor racks only at the initial site of installation of geomaterials, in fact, until their filling, with their subsequent removal. Further stretching does not require the use of anchors, since the geotextile and geogrid will be held by a layer of the filled material;

- if necessary (repair of the railroad track without removing the rail-sleeper grid), a device is installed on the Stacker for lifting the rail sleeper lattice, as well as devices for feeding geomaterials into the basement space, devices for stretching the geomaterials, backfill, planning and compaction of the bulk material in the working position in the basement space.

In addition, the proposed mechanized method of laying geosynthetic materials (geotextiles and bulk geogrid) in the construction of the road is characterized in that:

- sections of the geogrid are fastened in the longitudinal direction (the transverse size of the section is determined by the project and is implemented by the manufacturer of the geogrid) in order to form an expanded cellular structure in the stretched state over the area specified by the project.

The geogrid section is made of polymer tapes of a certain length, width and height, welded together in a checkerboard pattern with a step that determines the size of the cell. The geometric parameters of the tapes and the welding pitch are set in the project. A characteristic feature of the design of the geogrid section is the presence of two narrow tapes, welded strictly in the center between the two extreme tapes, which form two (upper and lower) pockets along the length of the section on each side. With their help, when stretching the section, interaction with the working bodies of the Stacker stretching mechanism is carried out;

- the working bodies of the stretching mechanism of the road car are in the form of plates, disks, boxes, etc., structurally conjugated with sprockets, or other structural elements that interact with the walls of the geogrid when moving the geogrid, ensuring its reliable fixation without disruption.

Between the set of essential features of the claimed object and the achieved technical result there is a causal relationship, namely:

- the use of the Stacker in the specified method, when the stretching of the geomaterials to the area determined by the project is carried out by the Stacker mechanisms, replaces the work of a large number of road workers (for example, when using the manual method, laying, stretching and fixing the volumetric geogrid in the form of 2.5 × 5 m modules in the laid state is carried out by a team of 10 people with an average productivity of not more than 60 m / h, while using the Stacker, similar operations can be performed at a speed of 90-150 m / h, while bsluzhivayuschego staff of no more than 5 persons);

- with the manual method of laying geomaterials, the connection of the sections of the geogrid is carried out at the place of work, with the mechanized method, the sections are fastened together previously to the length required by the project (hundreds of meters), which significantly speeds up the process as a whole;

- compact allocation of the stock of geosynthetics used directly on the Stacker, or on platforms connected to it, provides the ability to carry out repair work on long sections (up to 1,500 meters without additional loading with geomaterials);

- a fundamental change in the design of the geogrid section, aimed at creating pockets along the edges of the combined module, allows using the working bodies (plates, boxes, discs, etc.) of the Stacker stretching mechanism to feed and stretch the geogrid to the required length without the use of manual labor;

- bonding geogrid and geotextile to the ground at the initial stage of work allows pulling them with the pulling force of the Stacker from the containment devices (drum, rack, roll) with the simultaneous spreading of Stacker devices on the equipped surface, which excludes the use of manual labor for these purposes (except for the need for installation and extraction of several temporary anchor racks);

- filling the cells of the expanded geogrid with bulk material, which occurs immediately after their formation during stretching, allows the use of temporary anchor racks only at the initial site of installation of geomaterials, that is, until they are filled up. For further installation, anchors are not required, since the geotextile and geogrid will be kept from being displaced by the weight of the filled material. Such a solution to the issue of fixing geomaterials significantly reduces the required number of anchor racks and reduces the time of their installation and removal.

- the possibility of placing on the Stacker intended for the repair of the railway bed, devices that allow work under the raised rail-sleeper grid without its dismantling in automatic mode without the use of manual labor, unacceptable by safety regulations, and also eliminates the need for bulky road equipment (bulldozers, vibratory rollers) for planning and compaction of the bed of bulk material during manual installation, which also leads to the removal and reinstallation of the rail-sleeper solution Christmas trees.

The claimed technical solution for the method of mechanized laying of geomaterials in the road structure in comparison with the closest analogue can significantly reduce the number of road (track) workers engaged in manual labor, reduce the overall technological time for road work, and save the necessary auxiliary materials (temporary anchor racks).

The essence of the proposed technical solution is illustrated by the following illustrations.

Figure 1 shows a diagram of the Stacker used to implement the method. As an example of a device for containing a volumetric geogrid, a drum is shown. The working bodies of the geogrid stretching mechanism are box-shaped.

Figure 2 shows a section along aa (figure 1) of a stretched geogrid with working bodies (box edges) inserted into the upper (B) and lower (C) pockets of the Stacker stretching mechanism.

The stacker used to implement the proposed method can be schematically represented as follows (see figure 1). Drum 2 is installed on platform 1 of the Stacker with a geogrid 3 wound on it. On platform 1 of the Stacker, the following are also reinforced:

- guide rollers 4 and 5;

- a stretching device 6 with boxes 7 and 8 inserted with their ribs in the upper (B) and lower (C) pockets on the left and right sides of the geogrid section (see figure 2), and with asterisks 9. The boxes are angled relative to each other G, providing at a given length stretching the geogrid from the initially folded state to the final width;

- a roll of geotextile 10, the stock of rolls is comparable with the length of the geogrid located on the drum;

- a container or device 11 for bulk material;

- beam 12 with vibrating plates 13 for profiling and compaction of bulk material.

To simplify the drawing, the capacity for the backfill material 11 and the beam 12 for its vibration compaction are shown not connected to the platform.

For the initial fastening of geomaterials to the ground, temporary anchor posts D.

The mechanized method of laying geomaterials (geotextiles and bulk geogrid) is as follows. Platform 1 of the Stacker is installed on the road section being repaired, on which the technological operations preceding the installation of geomaterials have already been completed. Geogrid and geotextiles are removed from drum 2 and from roll 10 to a comparable length. The extraction is carried out manually or using manual or electric winches (not shown in the diagram). Using the rollers 4 and 5, the geogrid is rotated in the transverse plane to the required angle to install the geogrid on the edge when stretched. Geotextiles are expanded under the geogrid to the full width. The stretching device 6 is placed above the geogrid, its boxes 7 and 8 are inserted with their ribs into the upper B and lower B into the pockets of the geogrid section 9 on each side and are bent at an angle Г corresponding to the geogrid stretching to the entire width. The fingers of the stars 9 are mated to the cells of the geogrid. The ends of the geomaterials stretched in the described manner are fixed on the subgrade with anchor posts D. The design of the stretching device does not impede the movement of the Stacker. During the movement of the Stacker by its pulling force, the geomaterials, attached at their ends to the subgrade, are removed from the drum 2 and roll 10, the geogrid is expanded over the entire width by the edges of the boxes 7 and 8 of the stretching device 6, forming a wedge in the plan directed towards the Stacker, and spreading to the sides the extreme tapes of the geogrid, and, consequently, stretching the entire geogrid. Asterisks 9, rotating under the influence of geogrid cells moving relative to them, prevent the geogrid from slipping from boxes 7 and 8 of the stretching device 6, the geotextile is unwound under the geogrid throughout the entire width of the roll, the stretched geomaterials are filled in from the bunker 11, the beam 13 is leveled and compacted by the beam 13 with vibrating After filling several rows of cells of the stretched geogrid, it is firmly fixed on the subgrade by the weight of the filling material, so temporary anchor posts B are removed. The process continues until all geomaterials are used up, after which the drum and roll are changed or replenished, depending on the design of the Stacker. The filling mixture in the tank 11 is also replenished, if necessary.

The technical result obtained is expressed in a greater efficiency of the method than existing today, since it involves the involvement of a minimum number of road (track) workers and allows for a large capacity of devices for maintaining geomaterials (roll, drum, etc.) after a single fixing of geomaterials to produce long, continuous operation on their installation, significantly reducing the technological time allotted for this operation with minimal use of anchor racks (anchor racks accidentally forgotten in ozhnom canvas, can be the cause of the accident road vehicles).

According to preliminary calculations of Russian Railways, the feasibility study for the “Complex for creating a protective sub-ballast layer reinforced with a volumetric geogrid”, the development of which is based on the described method, with an annual amount of work on laying a volumetric geogrid at 53 km, the beneficial effect will be 387,456 thousand rubles .

Claims (2)

1. The mechanized method of laying geosynthetic materials in the road structure, including preparing the subgrade, stretching the geotextile on the subgrade surface, stretching the sections of the bulk geogrid on the geotextile surface, filling the geogrid cells to the height determined by the project with bulk material, characterized in that the geosynthetics extracted from content devices, stretched by a specialized road machine, adapted to the place of work, prepared for arrangement of the subgrade, and the sections of the volumetric geogrid are installed on top of the geotextile and transformed into a cellular volumetric structure, filled with the material of the project located on the machine or the bin connected to it, then leveled and compacted to prevent displacement. 2. The method according to claim 1, characterized in that the sections of the volumetric geogrid before being installed in the content device are fastened in the longitudinal direction to the length determined by the project in such a way that, when stretched, the combined sections form a cellular volumetric structure of the required area, and the combined geogrid section is made of tapes due to the design of the height and length using two narrow tapes, welded strictly in the center between the two extreme tapes, which form along the length of the section on each side of two (Top and bottom) of the pocket are used for stretching the geogrid stretching mechanism working bodies of the machine.

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