How to build temporary roads. Construction of temporary roads. Traffic patterns for vehicles and mechanisms
Schemes of movement of vehicles and mechanisms.
To perform transport and loading and unloading operations, movement of construction vehicles performing various construction processes, their movement patterns and temporary roads are designed.
There are temporary motor roads and roads for self-propelled construction cranes. In some cases, their purpose is the same.
The basic layout of temporary roads at the construction site, created during the preparatory period, is maintained until the end of the final cycle of the main period, when new roads appear, made according to the permanent layout of the building design.
At certain stages of work, separate branches can be installed for access to new sites - warehouses, installed equipment, lifts, etc.
Changes are reflected in the construction plan or technical plan. maps (schemes)
production of certain types of work.
Entrances and exits to the construction site from main roads are provided according to the scheme of permanent roads.
Roads according to the temporary road scheme are built at the expense of the cost of construction and installation work (to the detriment of cost), therefore their length, location, width, design, materials used, and the possibility of reuse are the most important components in determining the minimum costs.
The nature of the location of temporary roads is determined by the planning and design solutions of buildings. See rec. 8.17
When constructing one-story buildings, temporary roads are installed on one side of the building, on both sides and around the building
If the width of the building under construction is up to 18 m, it is advisable to provide a road on one side, therefore, it can be a dead end.
A turning area of at least 12×12 m or a loop is provided here.
For larger sides of the building (more than 100 m), ring roads are built, and if the building is located on both sides, for intermediate values of the building width.
During the construction of industrial buildings, in addition to general site roads, roads are constructed along the spans inside the building
The width of roads depends on the intensity of cargo flows, directions of movement (number of lanes)
Single sided – 3.5 m
Double-sided – 6 m
They can have a widening of at least 3 m for travel and unloading of materials and structures. The length of such sections is from 15 to 45 m
The curvature radii of temporary roads are accepted for vehicles without trailers - 9 m, with trailers - from 12 to 18 m.
For the transport of some tower cranes, the turning radii of these roads can be even larger.
The distance from the road to the fence or warehouses is taken to be at least 1.5 m.
Unloading areas for vehicles are located in the area served by a crane.
Temporary on-site roads can be dirt, crushed stone or precast concrete slabs (solid or rutted). The choice of type depends on the characteristics of the soil at the construction site. Dirt roads are made in dense soils and, if necessary, are compacted with crushed stone. On weaker soils, roads are made of crushed stone, and on weak-bearing soils, roads are made of prefabricated reinforced concrete slabs. Track-type roads are made with a gauge width of at least 0.6 m
Let's consider temporary roads for vehicles made of reinforced concrete slabs
Dead-end road with a turning area
Widening the road for parking
Turning patterns from slabs 6× 1.75 m and 3× 1.75
Figure - Types of temporary roads:
A - soil, B - crushed stone, C - solid made of reinforced concrete slabs, D - track made of prefabricated reinforced concrete slabs, 1 - crushed stone, 2 - precast reinforced concrete slabs
In order to reduce the costs of temporary structures, when developing a construction plan, if possible, temporary dirt and crushed stone roads should be located in the areas of designed permanent roads.
Initial data for designing temporary roads for self-propelled vehicles
jib cranes are:
Crane movement diagram
· Crane type
Loads created by a crane
· Technical (laboratory) conclusions about soils under the road
· Technical characteristics of precast concrete slabs or other products (materials) that are used as road bases
· Period of the year
Duration of operation
The design of temporary roads for construction cranes is determined by calculating the bearing capacity of soils. For cranes for automobiles, pneumatic tires and special applications. The chassis determines the amount of stress in the soil under the crane's outrigger, which is compared with that allowed for the soil of a given road.
When the lifting capacity of self-propelled jib cranes is 50 tons or more, it is necessary to check by calculation not only the bearing capacity of the soil, but also the calculation of precast reinforced concrete slabs for bending, because the load on each support can exceed 800 kN.
To check the bearing capacity of the soil under the crane tracks, a design diagram is adopted when installation is carried out with the boom located across the crane tracks.
On the construction plan it is written -
· Road diagram indicating dimensions, turning radii, direction of movement, entry and exit, type of surface, places for cleaning and washing wheels, location of installation of the traffic diagram.
Roads at a construction site require daily cleaning, and before each trip to permanent roads, vehicles require not only cleaning, but also washing.
The rules for protecting the natural environment after washing dirty water before it is discharged into drains must be cleared.
To solve these problems, at the exit from the construction site, vehicles are washed at specially built sites with wastewater treatment facilities.
Treatment facilities for car washing use two types - underground - made of reinforced concrete
And aboveground - metal
A stand with a traffic diagram is placed at the entrance to the construction site. The board shows a construction site plan with
Damaged by buildings under construction, open and closed warehouses, temporary and permanent roads, traffic directions, fire hydrants, etc.
Active and temporary
underground, overhead and overhead networks and communications
Existing utility networks are identified on the general plug and geo-base of the construction site. They are considered in two aspects:
shifted and remaining at the construction site for the entire main period of construction of the building or until the completion of construction of the engineering structures that replace them, after which they are dismantled.
The relaying of permanent utility networks is carried out during the preparatory period, therefore they are shown only on the construction plan of the preparatory period.
Since existing underground communications influence the adoption of certain decisions when designing work technology, it is necessary to take them into account when drawing up
· Road design schemes
· Rail track design
· Roads for self-propelled jib cranes, etc.
Operation of lifting machines in the security zone of power lines
A great limitation is exerted by overhead power lines, which impose strict restrictions on the technology of work due to the formation of zones of constantly operating hazardous production factors. The dimensions of these zones depend on the voltage in the power line and range from 1.5 – 9 m in each direction from the wires
7.1. Construction and installation work using lifting machines in the security zone of an existing power line with a voltage of more than 42 volts should be carried out under the direct supervision of the person responsible for the safe performance of work with lifting machines, with written permission from the organization that owns the line and a work permit (Appendix 2) for carrying out work in places where hazardous or harmful factors are present, issued to the immediate supervisor of the work, and a permit (Appendix 3) for carrying out work with lifting machines near an overhead power line, issued to the crane operator (operator, driver). When installing lifting machines in the security zone of an overhead power line, it is necessary to remove the voltage from the overhead power line.
7.2. The security zone along the overhead power line in accordance with GOST 12.1.051-90 is established in the form of an air space above the ground, limited by parallel vertical planes spaced on both sides of the line at a horizontal distance from the outer wires specified in Table 4 and shown in Figure 28.
Table 4 - Security zones along overhead power lines
| Distance, m | ||
| minimum | ||
| Up to 1 | 1,5 | 1,5 |
| Over 1 to 20 | 2,0 | 2,0 |
| Over 20 to 35 | 2,0 | 2,0 |
| Over 35 to 110 | 3,0 | 4,0 |
| Over 110 to 220 | 4,0 | 5,0 |
| Over 220 to 400 | 5,0 | 7,0 |
| Over 400 to 750 | 9,0 | 10,0 |
| Over 750 to 1150 | 10,0 | 11,0 |
A section of the dangerous zone of a power line, in which the operation of lifting machines is prohibited, but the movement of a crane across a power line is allowed.
A section of the dangerous zone of power lines, in which the operation of lifting machines and the presence of people and crane structures when moving without turning off the voltage is prohibited in all cases.
Boundary of the power transmission line security zone (see Table 4);
Boundary of the danger zone of power lines (see Table 5).
Figure 28 - Operation of cranes in the security zone of power lines
Table 5 - Boundaries of hazardous areas
| Voltage, kV | Distance from people, tools, devices and temporary fences they use, m | Distances from mechanisms and lifting machines in working and transport positions, from slings, lifting devices and loads, m | |
| Up to 1 | On overhead lines | 0,6 | 1,0 |
| In other electrical installations | Not standardized (no touching) | 1,0 | |
| 1-35 | 0,6 | 1,0 | |
| 60, 110 | 1,0 | 1,5 | |
| 1,5 | 2,0 | ||
| 2,0 | 2,5 | ||
| 2,5 | 3,5 | ||
| 400, 500 | 3,5 | 4,5 | |
| 5,0 | 6,0 | ||
| 800 (DC) | 3,5 | 4,5 | |
| 8,0 | 10,0 |
7.3. The security zone along underground cable power lines is established in the form of a plot of land limited by parallel vertical planes located on both sides of the line at a horizontal distance of 1 m from the outer cables.
7.4. The dangerous zone along an overhead power line, in which there is a danger of electric shock, is the space enclosed between the vertical planes spaced from the outermost live wires at an appropriate distance. The boundaries of hazardous areas within which there is a danger of electric shock are established by SNiP 12-03-2001 (Appendix 4) in the dimensions indicated in Table 5.
7.5. If it is justifiably impossible to relieve the voltage from an overhead power line, the work of construction machines in the security zone of the power line is permitted provided that the following requirements are met:
a) the distance from the lifting or retractable part of the construction machine in any position to the nearest wire of a live overhead power line must be no less than that specified in Table 6.
b) machine bodies, with the exception of tracked vehicles, are grounded using the inventory portable grounding.
Table 6 - Permissible distances when operating machines in the security zone of energized power lines
| Overhead line voltage, kV | Distance, m | |
| minimum | minimally measurable by technical means | |
| Up to 1 | 1,5 | 1,5 |
| Over 1 to 20 | 2,0 | 2,0 |
| Over 20 to 35 | 2,0 | 2,0 |
| Over 35 to 110 | 3,0 | 4,0 |
| Over 110 to 220 | 4,0 | 5,0 |
| Over 220 to 400 | 5,0 | 7,0 |
| Over 400 to 750 | 9,0 | 10,0 |
| Over 750 to 1150 | 10,0 | 11,0 |
7.6. To perform work in areas of hazardous production factors, the occurrence of which is not related to the nature of the work performed, a permit is issued in accordance with the form of Appendix 2.
The work permit is issued to the immediate supervisor of the work (foreman, foreman, etc.) by a person authorized by order of the head of the organization. Before starting work, the work manager is obliged to familiarize workers with work safety measures and issue instructions and write them down in the work permit.
7.7. When carrying out work in the security zone of a power transmission line or within the boundaries of breaks established by the rules for the protection of high-voltage electrical networks, a work permit can be issued only with the permission of the organization operating the power line.
7.8. Work carried out by lifting machines at a distance of less than 30 m from their lifting sliding part in any position, as well as from the load to the vertical plane formed by the projection onto the ground of the nearest wire of an overhead power line energized by more than 42 V, is carried out according to work permits in accordance with Appendix B, issued to the crane operator (operator, driver) and defining safe working conditions.
7.9. The operating conditions for lifting machines in the security zone of power lines or closer than 30 m from the outermost wires are developed in the PPR. An application for crane operation in the security zone of a power line is submitted no less than 12 days before the start of work to the owner of the power line.
The installation of cranes moving along rail tracks in the security zone of overhead power lines is agreed upon with the owner of the line. The permit for such an installation for construction and installation work is stored together with the work project.
7.10. The operation of jib cranes and manipulator cranes under non-disconnected contact wires of urban transport can be carried out provided that the distance between the crane boom and the contact wires is maintained at least 1 m when installing a limiter (stop) that does not allow reducing the specified distance when lifting and moving the boom.
7.11. The work of lifting machines near power lines is carried out under the direct supervision of the person responsible for the safe performance of work by lifting machines, who indicates to the crane operator (operator, driver) the installation location of the lifting machine and to make an entry in the logbook about the permission of the work: “Installation of the crane (manipulator crane, lift) in the place indicated by me. I authorize the work" and put my signature and date.*
Safety fences must be installed along the boundaries of the danger zone.
Temporary networks and communications may change at different stages of building construction. However, inputs, outputs, main lines are constant.
When designing temporary networks, it is necessary to calculate their power based on maximum flow. In this case, the connection of temporary networks to permanent ones is carried out taking into account the available capacity for construction and the location of tie-in points.
On the construction plan they put:
· Permanent and temporary networks
· Power lines and hazardous areas from their influence
· Temporary engineering structures.
Placement of permanent, under construction and temporary buildings and structures, storage areas and enlarged assembly of structures
The placement of permanent and under construction buildings and structures on the construction plan is carried out according to the general plan of the facility with a preliminary clarification of the situation at the site of the future construction site. Temporary buildings and structures are selected based on the calculation results.
The territory within the boundaries of the site allocated for construction is divided into several zones:
· Area of production of main types of construction work
· Area for performing auxiliary processes (loading and unloading operations, assembly work, concrete preparation, etc.
· Areas for storage of products and materials, pre-assembly
· Area of administrative and sanitary premises
When designing the locations of sites and premises for storing materials and structures, enlarged assembly of structures, it is necessary to take into account:
Closed temporary buildings (warehouses, workshops) are located outside the boundaries of hazardous areas and must have vehicle access
Open areas for storing products and materials are designed in areas where cranes operate, outside areas with constantly operating hazardous production factors, and the dangerous zone where objects fly off when falling from a building.
In this case, it is necessary to take into account the technical characteristics of load-lifting cranes from the point of view of the possibility of lifting (unloading) products at a maximum distance on the site
Sites for the enlarged assembly of structures are located outside the range of the main assembly crane.
Platforms for the installation of tower cranes must have minimum dimensions determined by calculation based on technical characteristics.
Technological diagram for unloading reinforced concrete elements with a self-propelled jib crane and conditions for their storage
1-tap; 2-motor transport; 3-pyramids for wall panels; 4-place storage of slabs, floors; 5 - temporary road; 6 - road widening
In the diagram: the crane location area is located on a special site adjacent to the temporary road, which allows the vehicle to be positioned and the required boom reach to be ensured.
Storage of structures should be carried out within the reach of the tower crane, with more massive structures located closer to the axis of the crane.
The warehouse area is provided with passages in the longitudinal and transverse directions.
Storage areas must have a hard surface, minimal slopes (for water drainage), and be non-flooding, for which purpose ditches are installed along the perimeter. They are made of prefabricated reinforced concrete slabs on a layer of sand or have a sand and gravel base.
A building under construction is shown as its outline with the main axes and axes defining its configuration and the required dimensions between them
Permanent and temporary buildings are depicted in the form of their outlines.
The platforms additionally have inscriptions according to their purpose and overall dimensions.
The construction plan shows the movement patterns of workers in the form of pedestrian zones:
Entrance to the construction site (checkpoint)
To the sanitary camp (dressing rooms)
To workplaces
In warehouses, etc.
To lift people to the floors, staircases are used, the construction of which should not lag behind the construction of other structures of the floor (tier) of the building.
At a height of more than 25 m, passenger-and-freight lifts are used to lift workers (at the rate of one per one to two sections of the house)
Pedestrian paths are made of gravel-sand mixture or prefabricated reinforced concrete slabs. For slopes greater than 20°, pedestrian paths are equipped with ladders or stairs with guardrails
Ensuring cleanliness in workplaces and aisles is an indispensable condition for production culture and worker productivity.
Construction waste is removed in two ways:
· It is lowered through closed chutes into waste bins, under which, after a certain time, vehicles are supplied and the waste is removed
· Using cranes (lifts), garbage collected in containers from the floors is lowered to specially designated areas
In the sanitary and household zone, places are provided for installing containers for collecting household waste.
The construction plan shows the installation locations of waste bins and containers, indicating their dimensions and location.
The placement of sources and means of power supply and lighting of the construction site, the location of grounding loops are indicated on the construction plan in the form of diagrams (according to calculations)
The minimum volume of temporary power supply for the construction of a building is taken according to the calculation of the required electrical power
and determining the type of transformer, starting devices, sections, lengths and grades of wires, arrangement of electrical equipment on the construction plan
For electrical safety purposes, all metal parts of electrical equipment must be grounded (tower cranes, hoists, switchgears, etc.)
Grounding devices are most often performed along contours. The construction plan shows the contours of the grounding rods, their sizes, the distance between them, connecting conductors, jumpers between the rails of crane tracks, etc.
To ensure the accuracy of the geometric parameters of the buildings under construction, a geodetic alignment base is created at the construction site in the form of a alignment network with offset along the contour of the main axes of the building.
When constructing groups of buildings, they show the locations of the planning and elevation signs.
When constructing individual buildings, only signs for securing the main axes of the building are shown on the construction plan - at least 4 for each axis. Signs of the high-rise alignment base are combined with the planned base and located at a distance of at least 1.5H (height) of the building.
4.10. Axial signs should generally be shown at a distance of 15 - 30 m from the building outline.
The shortest distance allowed is 3 m from the edge of the pit, the boundary of the soil collapse prism; the largest is one and a half height of a building, structure, but not more than 50 m.
The distance between axial marks securing intermediate transverse axes can reach 50 - 100 m.
When fixing the alignment axes of tunnels, overpasses, and retaining walls of considerable length, intermediate signs should also be shown on the longitudinal axes every 50–100 m.
An example with forced limitation of the service area is given in Figure 27. The diagram shows the limitation of the service area by a crane using forced limitation of the boom rotation angle in cramped conditions.
1 - boundary of the crane service area; 2 - boundary of the zone dangerous for people during movement, installation and fastening of elements and structures; 3 - line limiting the crane service area; 4 - warning line about limiting the service area of the crane; 5 - boundary of the danger zone from the building under construction; 6 - platform for receiving mortar and concrete mixture; 7 - location of the control load; 8 - space for storing removable load-handling devices and containers; 9 - construction waste collection site; 10 - parking area for vehicles under unloading; 11 - platform for tilting columns; 12 - stand with sling diagrams and a table of load masses; 13 - crane power supply cabinet; 14 - grounding of rail crane tracks; 15 - connecting conductors; 16 - pedestrian paths; 17 - entrance to the construction site; 18 - departure from the construction site; 19 - direction of transport; 20 - temporary road; 21 - storage area for materials and structures; 22 - fencing of rail crane tracks; 23 - temporary wooden fence; 24 - temporary picket fence; 25 - sign No. 2 limiting the crane service area; 26 - sign warning about the operation of the crane; 27 - vehicle wheel washing point) in the area between the outermost crane stops on the rail crane track according to Figure 12.
1 - construction site fencing; 2 - boundary of the danger zone near a building under construction; 3 - boundary of the zone dangerous for people during movement, installation and fastening of elements and structures*; 4 - boundary of the crane service area; 5 - tower crane; 6 - sanitary facilities.
________________
* - the boundary of the dangerous zone is determined in accordance with clause 5.4 of these “Instructions...”.
The symbols used in the figures are presented in Appendix G.
Figure 12 - Zone boundaries when operating tower cranes
5.3. The boundaries of the service areas of jib cranes and loader cranes are determined by the maximum reach () according to Figure 13.
1 - construction site fencing; 2 - boundary of the danger zone near a building under construction; 3 - boundary of the zone dangerous for people while moving, installing and securing elements and structures in one parking lot*; 4 - the same, taking into account all parking lots; 5 - boundary of the crane service area; 6 - jib crane.
________________
* - the boundary of the dangerous zone is determined in accordance with clause 5.4. of these "Instructions...".
Figure 13 - Zone boundaries when operating a jib crane (manipulator crane)
Construction site power supply and outdoor lighting
Energy supply to the construction site is carried out in accordance with the construction organization project from the source specified in the approval for the development of project documentation. As a rule, this is the closest transformer substation. If necessary, due to lack of power, reconstruction of the substation is provided.
All work related to providing the facility under construction with electricity is carried out during the preparatory period. A distribution board is installed at the construction site at the point indicated on the construction plan.
Lighting of the construction site is carried out from the installed distribution board. External lighting lamps or Injectors are used as lamps, installed in places that prevent them from being damaged during construction and installation work.
The illumination of the construction site must comply with approved standards.
Temporary water supply and sanitation
Temporary water supply is provided from the source provided for in the construction organization project, agreed upon at the design stage with the owner of the existing water supply network. The temporary water supply is inserted into a pipe running inside the well with the installation of a shut-off valve and a water flow meter - a water meter.
In cases where the existing pipeline does not provide additional flow, it is necessary to replace the pipes with a larger diameter.
If the facility under construction is located at a significant distance from the existing water supply network, water from a drilled well can be used for the period of work. In exceptional cases, for small volumes of work, the use of imported water is allowed.
The water drainage required during the operation of domestic premises can be carried out into the existing sewerage system passing near the construction site. If there is no such drainage system, it can be organized into a cesspool.
Currently, dry toilets are widely used, the number of which on the site is determined depending on the maximum number of workers per shift.
Technological maps for performing certain types of work
The technical map is an integral part of the organizational and technological documentation for the construction of buildings and should form an independent section of the production project.
Main sections
1. Scope of application (description of production methods)
2. Material and technical resources:
Need for material resources
Need for technical resources
Selecting an assembly crane based on technical and economic indicators
3 Hourly (or shift) schedule for installation of typical cells
4 Calculation of labor costs and machine time
5 Technology and organization of the complex installation process
6 Quality requirements. Operational quality control of work
7 Safety precautions
8 Technical and economic indicators according to the technological map
Technological maps are developed by type of work for construction processes, as a result of which completed structural elements are created, as well as parts of buildings, etc.
Design of temporary roads on the construction plan
At construction sites, normal and narrow gauge roads and railways are used as temporary roads. The construction of temporary railways is carried out by specialized organizations; the construction of highways is carried out, as a rule, by general construction organizations.
When routing roads, it is necessary to ensure transport access to the operating area of cranes, lifts, warehouses, pre-assembly sites, workshops, mechanized installations, etc. It is necessary to make maximum use of existing and planned roads.
Temporary roads should be designed in accordance with SNiP 12-03-2001. The main parameters of temporary roads include: number of traffic lanes, width of the roadbed and roadway, curvature radii, estimated visibility, maximum longitudinal slope. All these parameters are determined in accordance with the requirements of SNiP.
Areas of the road located within the area of installation or movement of cargo are dangerous. On the construction plan, these sections of roads are highlighted with double shading, and during the construction process measures are taken to ensure the safety of people and vehicles located within the danger zones. Additional conditions that ensure traffic safety on a construction site include speed limits, entry bans and other conditions regulated by traffic rules and agreed upon with the State Traffic Safety Inspectorate and the Ministry of Internal Affairs.
When determining the design of the pavement of temporary roads and the consumption of material and technical resources for their construction, it is extremely important to be guided by the instructions of SNiP.
The construction road includes access roads connecting the construction site with the general road network, and intra-construction roads along which goods are transported within the site. Access roads, as a rule, are made permanent, and internal roads are temporary. These driveways are laid before the construction of basic facilities begins.
Roads on construction sites can be either dead ends or ring roads. At the end of dead-end roads there should be turning areas, and in the middle part, if it is extremely important, there should be sidings. Based on the standard overall dimensions of the car (a rectangle with a width of 2.5 and a height of 3.8 m), the width of the roadway for single-lane traffic is taken to be at least 3.5 m, and for two-lane traffic - 6.0 m. If the road is designed as a single-lane road, then widenings must be provided in the proposed places for unloading vehicles, making the total width of the road at least 6 m.
When using heavy vehicles with a carrying capacity of 25... 30 tons or more, the width of the roadway increases to 8 m.
The curvature radius of roads is dictated by the maneuverability of individual vehicles and road trains. Typically, the minimum radius of the curve is 15 m; in this place the width of the roadway is increased - with a road width of 3.5 m at the curve it will be 5 m, the greatest slope is 0.08.
Structurally, highways consist of subgrade and road pavement. To drain surface water, the road is given a gable slope on straight sections of the route, and a single slope on curved sections.
Road pavement consists of several layers - an underlying sand layer, a load-bearing base (crushed stone, concrete, reinforced concrete) and a coating. It is important to note that in order to reduce costs at the construction site, it is advisable to install future permanent roads without a top covering. It is even more effective to lay a temporary coating of reinforced concrete road slabs over the sandy base. In this case, the main coating should be carried out before putting the facility into operation.
Slabs are used as reinforced concrete road slabs; rectangular and wedge-shaped. Rectangular road slabs (length 2.5...3.0 m, width 1.0... 1.5 m, thickness 0.14...0.22 m and weight 0.63... 1.8 r) are simple to install, suitable for use immediately after installation at any time of the year and in any weather.
The costs of constructing, repairing and maintaining such roads under conditions of traffic intensity typical for construction sites usually pay off in 1.5...2.0 years. Prefabricated slabs are the property of the construction organization and can be reused by it.
Design of temporary roads on a construction plan - concept and types. Classification and features of the category "Design of temporary roads on the construction plan" 2017, 2018.
→ Construction of buildings and structures
Construction site roads
Construction site roads
Construction roads include access roads connecting the construction site with the general road network, and intra-construction roads along which goods are transported within the site. Access roads, as a rule, are made permanent, and internal roads are temporary; These driveways are laid before the construction of the main facilities begins.
Roads at construction sites can be dead ends or roundabouts. At the end of dead-end roads there should be turning areas, and in the middle part, if necessary, sidings. Based on the standard dimensions of the car (a rectangle with a width of 2.5 and a height of 3.8 m), the width of the roadway for single-lane traffic must be at least 3.5 m, and for two-lane traffic - 6 m. If the road is designed as single-lane, then Widening should be provided at the intended places for unloading vehicles, the total width of the road should be at least 6 m (Fig. 3.2).
When using heavy vehicles with a carrying capacity of 25...30 tons or more, the width of the roadway increases to 8 m. If large and long loads are delivered to the construction site, the width of the road can be further increased.
The curvature radius of roads is dictated by the maneuvering capabilities of individual vehicles and road trains, i.e., their turning ability when moving forward without using reverse. Typically, the minimum radius of the curve is 15 m; at this point the width of the roadway is increased - with a road width of 3.5 m at the curve it will be 5 m.
Structurally, highways consist of subgrade and road pavement. To drain surface water, the road is given a gable slope on straight sections of the route, and a single slope on curved sections.
Rice. 3.2. On-site roads:
1 - ring road; 2 - dead-end road; 3 - passing; 4 - turn; 5 - widened turn of the ring road
Road pavement consists of several layers - an underlying sand layer, a load-bearing base (crushed stone, concrete, reinforced concrete) and a coating. To reduce costs during the construction period, it is advisable to build future permanent roads without a top covering at the construction site. Only the lower layers of the road are laid; it is even more effective to lay a temporary covering of reinforced concrete road slabs over the sandy base. In this case, the main coating should be carried out before putting the facility into operation.
Rice. 3.3. Temporary roads made of reinforced concrete slabs:
a - track, single track made of rectangular slabs; b- the same, double track; c - widening of the road at the junction of vehicles; g - solid, made of wedge-shaped slabs; 1 - single-track section; 2 - double track section
Rectangular and wedge-shaped slabs are used as reinforced concrete road slabs (Fig. 3.3). Rectangular road slabs (length 2.5...3.0 m, width 1.0... 1.5 m, thickness 0.14...0.22 m and weight 0.63... 1.8 r) are easy to manufacture and work with on the construction site, can withstand increased loads, and are suitable for use immediately after installation at any time of the year and in any weather. Roads are often constructed with rutted tracks - single- and double-track with sidings. Wedge-shaped slabs make it possible to cover the entire width of the road at once; the radius of curvature at turns can be any. On straight sections, the slabs alternate, placing them on either the wide or narrow side. For such slabs there is no need to construct individual sections of the road (especially at turns) in a monolithic design.
The costs of constructing, repairing and maintaining such roads under conditions of typical construction traffic intensity usually pay off in 1.5...2 years. Prefabricated slabs are the property of the construction organization and are intended for repeated use.
The design of a temporary road is selected depending on several factors:
Duration of construction;
Carrying capacity of vehicles and traffic intensity;
Hydrogeological conditions of the work area;
Seasons.
Depending on these factors, temporary roads can be: unpaved; ground with reinforced coating; with a hard surface, including prefabricated reinforced concrete slabs.
Dirt roads are constructed under favorable hydrogeological conditions (on soils of category IV and higher) and during construction in winter when the soil freezes. The transverse terrain of the road is profiled with a slope of 5-6 o from the center to the sides using a motor grader.
Paved roads are installed when construction lasts more than one year or under unfavorable hydrogeological conditions. They are usually made from prefabricated reinforced concrete slabs laid on an underlying layer of sand 15-25 cm thick. As a rule, road slabs can withstand three to four times turnover, which is greatly facilitated by laying the slabs on a leveled underlying layer and fastening them together by welding or wire twists.
Figure 6 – Classification of temporary road structures
Natural dirt roads
They are installed with low traffic intensity (up to 3 vehicles per hour in one direction) in favorable soil and hydrogeological conditions. Profiling of the roadway is carried out to drain water during precipitation and melting snow.
Figure 7 – Design of a dirt profiled road
Dirt improved roads
If they experience heavy loads (up to 60 kN per axle) or are in less favorable conditions, they are strengthened with crushed stone, gravel, slag, tar or bitumen binder, and compacted with a roller.
Without the use of binder
gravel roads
Coverings made from crushed stone and gravel optimal mixtures are used for roads of categories III - IV with a subgrade made of sandy-clayey or sandy soils and in the presence of gravel or crushed stone materials in the construction area. Crushed stone and gravel coverings are arranged in a crescent-shaped profile over the entire width of the subgrade.
For the construction of gravel coverings, quarry gravel material or artificially composed mixtures are used, the optimal compositions of which are given in Table. 3.
Gravel coverings on the subgrade are arranged in two or three layers, depending on the estimated thickness of the covering. The thickness of individual layers is assumed to be 15 - 20 cm.
Table 3 - Optimal mixture composition for gravel roads
For the construction of crushed stone coverings, natural or artificial crushed stone is used. Crushed stone of fractions 70 - 150 and 40 - 70 mm is used for the bottom layer, and only crushed stone of fractions 40 - 70 mm is placed in the top layer. To form the top dense layer and fill the pores, small fractions are used: 5 - 10, 10 - 20 and 20 - 40 mm. Their quantity should be 10 - 15% of the volume of crushed stone in the coating. The layers are evenly distributed with a bulldozer or motor grader across the entire width of the roadway and compacted from the edge of the roadbed to the axis of the road.
Figure 8 – Gravel road design
To deliver construction cargo to the construction site, it is necessary to construct temporary internal roads. Temporary roads are constructed after completion of the vertical planning of the territory, installation of drainages, drains and utilities, except for temporary ones. The construction of temporary roads must be completed before work on the construction of the underground part of the buildings begins.
Types of roads. Mostly roads are used on construction sites. Railways are used mainly in the construction of large industrial units.
Road design. When designing internal roads, the following tasks are solved:
1) a traffic pattern and the location of roads in the plan are developed;
2) parameters of roads and dangerous zones are established;
3) road designs are assigned, the scope of work and the necessary resources are calculated.
Traffic pattern and road layoutin respect of must provide access to the area of operation of assembly cranes, to large assembly sites, to warehouses, workshops, to utility rooms, etc. The route of temporary roads must be designed as closely as possible along the routes of future permanent roads. As a rule, construction roads should be ring roads, and passing and turning areas should be installed on dead-end roads.
When routing roads, the following minimum distances must be observed:
– between the road and the storage area – ≥ 0.5 ... 1.0 m;
– between the road and the crane tracks – ≥ 6.5 ... 12.5 m;
– between the road and the axis of the railway tracks – ≥ 3.75 m;
– between the road and the construction site fence – more than 1.5 m;
– between the road and the edge of the trench – more than 1.5 m.
Entrances and exits, directions of movement, turns, sidings, parking areas for unloading, and the location of traffic safety signs must be marked on the SGP.
Parameters of temporary roads are:
– number of traffic lanes;
– road curvature radius;
– the value of the calculated visibility.
On temporary roads, traffic is limited to one or two lanes.
The width of the roadway is taken at:
– single-lane traffic – 3.5 m;
– two-lane traffic – 6 m.
If vehicles weighing 25 tons or more (Maz, Belaz, etc.) are used to deliver goods, then the width of the roadway increases to 8 meters.
On roads with one-lane traffic, within sight, but not less than 100 m apart, it is necessary to arrange widening areas 6 meters wide and 12 or 18 meters long. The same platforms are arranged in places where materials are unloaded for any vehicle traffic pattern.
At the intersections of railways, continuous flooring, fencing and lighting are installed. The width of the roadway at railway crossings must be at least 4.5 m. Crossings are organized at an angle of 60 - 90 degrees and are equipped with sound and light alarms. If there is heavy traffic, barriers are installed.
Road curvature radii are determined based on the shunting properties of vehicles and road trains. The minimum radius of curve for construction trains is 12 m. In places of curves, the width of the single-lane road should be increased to 5 m.
Estimated visibility in the direction of travel for single-lane roads should be at least 50 m, and side (at an intersection) - at least 35 m.
Temporary roads that pass through the installation area are indicated by shading on the SGP.
Pass-through through hazardous areas is prohibited.
Temporary structures roads must be designed according to the loads arising from the movement of heavy vehicles.
Permanent roads for use during the construction period it is necessary to carry out in two stages. First, roads are made and one layer of asphalt concrete is laid. Towards the end of construction, the bottom layer is repaired and a new top layer is installed.
The designs of temporary roads depend on specific operating conditions and can be of the following types:
– natural soil profiled;
– soil of improved design;
– with hard surface;
– from prefabricated reinforced concrete inventory slabs.
Dirt roads are arranged at low traffic volumes (up to 3-4 cars per hour) in one direction. If roads experience heavy loads, they are strengthened with gravel, slag, sand-gravel-clay mixture, etc. Gravel is poured with or without a trough in 1-2 layers with compaction.
P 
Peaked roads with a load of 12 tons are best made from prefabricated reinforced concrete slabs. The slabs are laid on a sand bed of 10-20 cm. Road slabs with prestressing have proven themselves well.
Organization of on-site warehouses
On-site warehouses are organized for temporary storage of materials, structures, products and equipment during the construction process. Storage volumes should be kept to a minimum.
When designing on-site warehouses, the following tasks are solved:
1) determination of the volume of stocks of materials, structures and products to be stored;
2) calculation of warehouse area for the main types of material resources;
3) selection of rational types of warehouses and their placement on the construction site.