The highway is a very complex structure, for the construction of which a huge number of different aspects are taken into account. This is the load on the canvas, and the intensity of car traffic, and much more.
Track Performance
In this regard, for the full calculation of the transverse profile of the road, first of all, the characteristic of the traffic flow and the intensity of operation on the route under consideration are determined.
Basically considered parameters such as:
- The intensity of the use of the track. This concept includes an estimate of the number of transport units that have passed through a given section in the time allotted for measurements. In calculations, the intensity is taken as average, as well as planned and actual.
- The concept of traffic capacity refers to the number of vehicles passing through the transverse profile of a road at a specific time.
- The speed of the traffic flow is the average speed of all cars moving along the studied section of the route.
- Traffic density is the average number of vehicles that are simultaneously on the studied section of the route.
- The amount of cargo transported through the studied section of the road is called the load intensity.
There are also concepts such as roughness and evenness. They determine the quality of the roadway on the studied transverse profile of the road. All these data are necessary when working on the route both within the framework of its repair, and at the design stage.
How are classified
The transverse profile of the road depends on which category the highway belongs to. It can be a trunk, that is, one that connects the international routes. Passengers and goods of a transit category are transported along it.
Regional roads include roads connecting the capital of the state with the capitals of the regions. Territorial routes are roads connecting the settlements of certain areas. Highways of district significance connect district centers and small towns of a certain region.
The transverse profile of the road completely depends on the category of the route, since they all have their own load. The common between all types of tracks is only the term of their intended service. It is not less than 20 years. All this time, the transverse profile of the road should not require serious reconstruction or repair, even if the load on the track increases sharply. These possible bursts of congestion are taken into account during the design of the road.
Track
The term "track" is applied mainly to topographic roads, that is, plotted on a map or plan in the form of a horizontal diagram of its location. The track can also be viewed in a longitudinal profile to display the terrain and follow the road along it.
The longitudinal profile of the road during design is a very important component of the calculations. If this characteristic does not meet the requirements of safety and convenience for transport, then the soil in this place is removed, making the elevation differences of the road more smooth.
If the height difference is so sharp that it does not meet the requirements, then the lowlands fall asleep. In other words, the track is a direction in the diagram, taking into account elevations.
Road. Definition
The road device includes a carriageway, a roadside, a slope of a subgrade and a ditch. The roadway is with or without a dividing strip. It depends on the width of the canvas. For example, a dividing line is necessarily on roads with 2, 3 or more lanes.
The roadside is a soil coating at the same height as the road, its width may vary depending on environmental conditions and technical specifications for the design of the facility. Usually they try to make the roadside wide enough to stop the car safely for the main movement.
Earthen mound
The width, height and angle of slope of the earth depend on how high the road is built from ground level. Slope gives the road the necessary strength. It is calculated taking into account the materials used in the construction and soil characteristics. A soil cushion, the edge of which is a slope, is a multilayer structure consisting of various materials - pebbles, sand, gravel. Care of the slope is as important as the roadway, because if it collapses, then the whole road will sag.
The height of the embankment is largely dependent on the terrain along which the track runs. If heavy snowfall is possible in the region, then the embankment is made of sufficient height so that the snow does not fill the road. If the route runs through a flat steppe, in a hot region with low rainfall, then the embankment will be no more than 1 meter in height. The angle of the slope depends on what kind of load is planned for this road. On large highways with a high traffic density, the earthen slope has a very obtuse angle, which increases the strength of the road. Conversely, a low load on the road allows you to make the slope steeper with respect to the canvas. But in this case, additional strengthening will be necessary in the form of pillars, fences or plant roots.
Ditch
The cuvette serves as a drainage ditch, through which excess water is discharged from the embankment. The device of the road involves placing drainage pipes and channels in the cuvette, the main task of which is to protect the bulk of the road from erosion. This is especially true during the spring rains, coupled with massive snow melting.
Cross profile
The transverse profile of the road is a section of the web and its substrate perpendicular to the longitudinal axis of the road. How often is it used? The construction of roads widely uses precisely the transverse profile for the design and support of the installation of the cushion and the roadway lane itself.
Cross profile on the embankment
A typical transverse profile of a road displays a roadway with dividing lanes and a road edge, curbs, slopes and drains. All this is a prerequisite for operating the track.
There are various types of transverse profiles of highways. For example, these are profiles on embankments. This type of road is very common, in almost any area, in any climate region.
When constructing the track, it is important to make a streamlined profile. The height of the embankment can vary from 1 to 20 meters. A characteristic feature of this road is the streamlined shape of the pepper profile, which allows rainwater and melting snow to drain. The ditch is arranged by excavation along the earthen dumping of the road. If natural conditions allow, then the embankment of the road is made from soil taken along the canvas, if not, then it is brought from special quarries.
It happens that a paved road is not streamlined. In this case, it is absolutely flat, and water is removed from its surface using other technologies.
The construction of roads takes place not only on relatively flat soil, but also in remote mountain areas. In this case, streamlined and non-streamlined profiles are built on slopes. Installation of such a road is possible only at a certain angle of the slope. If it is more than permissible, then the road is transferred or the mountain is adjusted to the necessary conditions by explosives or drifters.
But on such a mountain road, with slopes, there are all the elements of the transverse profile of the road - the curb, the ditch and reserves, from which the soil for the embankment was taken.
Cross profile in the recess
In some cases, a paved road is required on a terrain that does not allow the embankment to be made in lowlands, in loose soil conditions or in the middle of arable fields. There are few such roads. But they are necessary. These are roads with a transverse profile in a recess.
They represent a streamlined profile recessed in the ground. If construction conditions permit, then a cell is arranged along such a road, which makes the canvas elevated, but not to the level of the upper edge of the soil.
The depth of such a road can be up to 12 meters down from the ground. And it doesn’t matter how wide it is. Even the transverse profile of a Category 4 road suggests that there are shelves in the recesses for organizing snow dumps, despite the fact that such a road has only 2 lanes.
A shelf is also necessary on mountain roads, as they have weathering and natural erosion of the rock. And small fractions, breaking away from the rocks, accumulate in special grooves along the canvas.
If the slope on the road with a transverse profile in the recess is quite high, then it is made in the form of ledges. This allows you to make the walls stronger, which keeps them from collapsing.
Classification
The technology of asphalting roads and their operation depend on the category of track. The first category includes roads with the number of lanes from 4 to 8 and the width of the roadway up to 15 meters. And the width of the subgrade along with the curb and the slope of the embankment can be up to 40-45 meters. Roads of the second category have 2 lanes with a total width of 7.5 meters and a total width of 15 meters.
Roads of the third and fourth categories also have 2 lanes, but differ in the width of the roadway and the width of each lane. The 3rd category includes tracks with a strip width of 3.5 meters, a roadbed of 7 meters and the entire road as a whole - 14 meters. And category 4 includes lanes with a width of 3 meters, 6 meters of road and 12 meters of the road itself.
The technology of asphalting roads relies precisely on these standards in most civilized countries. In addition, no matter what category the road under construction belongs to, it is necessarily equipped with ditches, drainage, a curb, and its slopes are reinforced with concrete or plants. Road markings are also required.
Additional facilities
Any route has a number of additional facilities that are necessarily included in the design documentation. Moreover, some of them are indicated in the transverse profile of the road. For example, a transverse pipe for a stream crossing a track.
Pedestrian bridges or underpasses can also be installed across the road . The road can go along the bridge, it is indicated in the plan as an additional construction of the route.
The bridge can pass not only over the river, but also over a deep ravine and gorge. In this case, it is called a viaduct and is arranged in the form of an openwork design, under which pedestrians or water transport are not supposed to move. The viaduct, as a rule, is single-lane, and rarely when intense traffic is carried out on it. Most often, a viaduct is created for the device of the railway.
Mountain roads are protected from snowfalls, avalanches and rockfalls by galleries. Concrete poles along the road belong to the same category of protective equipment. In the design documentation, they are called retaining walls.
Additional facilities include traffic police posts with all necessary facilities. There are bus stops on any road, even on international routes. Therefore, this structure refers to additional buildings.
The importance of tracks
In today's world, roads are everywhere. It is difficult to imagine a terrain or environment that has no roads. They can pass along mountain streamers and through the mountains themselves. Through the sands of hot deserts and impenetrable taiga forests. Even under the ocean floor, roads are laid, for example, under the English Channel.
Roads bring people and countries together. And these structures have existed for more than a century. It is enough to recall the Great Silk Road - the road connecting Europe and Asia. Without roads, there can be no economic growth and cultural exchange between countries and peoples.
In the old days, small ships transported goods and people. In this regard, the economy developed only in those countries where there were enough rivers. Those where there were few remained in cultural and commercial isolation.
Only thanks to modern roads, such a science as logistics began to develop. The engineering industry and the energy industry received a boost.
Conclusion
The construction of roads has become so profitable and at the same time laborious, that in all countries road institutes have begun to be organized in which young specialists comprehend the complexity of the construction process. A road engineer is able to design and then control the road construction process from scratch. And most importantly, correctly and economically monitor the state of the constructed facility.