Macesta-Progress-Abazinka road reconstruction project

1.2.2. Characteristics of the plan, profile of the roadway and road clothing.

According to the parameters of the plan and the longitudinal profile, the road section under consideration corresponds to category IV, passes in a mountainous area, has an asphalt concrete coating of hot fine-grained dense mixture of type B II of the class with a thickness of 4 cm, a hot coarse-grained porous mixture with a thickness of 6 cm. The base is two-layer: upper layer of coarse-grained porous hot black crushed stone asphalt mixture of Mark II, b cm thick, lower elephant of sand-gravel mixture with gravel content of 70% and 30% crushed stone thickness of 20 cm, underlying layer of sand-gravel mixture with gravel grain content of 6575%, thickness of 20 cm.

Shoulders from crushed stone fraction 2040 mm thick 12 cm wide 1 m.

IF width - 6.0 m

Width ZP - 10.0 m

Shoulder width - 2.0 m

Minimum radius of curves in plan - 40 m

Maximum longitudinal slope - 54.2 ‰

The size of small artificial structures - the width of the roadway

Type of road clothing - advanced, lightweight type.

The condition of road clothing is satisfactory, in some sections of the road the radius of the curves in plan and the longitudinal slope are not maintained.

1.3. Brief conclusions on section.

The natural and climatic conditions of the highway extension area have features in connection with the mountain terrain, which should be taken into account when developing a project for the reconstruction of this section of the highway.

The existing road of category IV has some deviations from the underlying standards, does not correspond to the radii of the curves in terms of the minimum permissible value for category IV. These departures significantly reduce traffic safety on a given section of the road.

As per technical condition, this area is in satisfactory condition

2. Justification of the new technical category and main parameters of the reconstructed highway.

In the course of road service, some time after the opening of traffic on it, in certain sections, difficulties begin to be created for unhindered passage of traffic flow, increasing as traffic intensity increases. Also, due to natural and other factors, the road cover is destroyed, which reduces traffic safety, capacity and is the cause of accidents.

In order to restore normal traffic conditions, reduce accidents and increase the efficiency of the use of road transport, individual places or the road as a whole are rebuilt, giving the road new qualities. Knowing the average daily traffic intensity in the initial year and the indicator of annual increase in traffic intensity, a promising intensity for 20 years is calculated, thus determining the new technical category of the road and its parameters.

Brief conclusions on section.

The reconstruction of the road according to category III standards will entail the reconstruction of some sections of the road. At the same time, it is necessary to strive to maximize the preservation of existing structures, reduce investment and labor intensity of work during the reconstruction of the road.

When assigning the parameters of the reconstructed road, we strive to ensure traffic safety and a decrease in investment, as a result of which, with the requirement of paragraph 4.1 [1] for design, we adopt standards based on the design speed (Table 10 [1]).

3 Design of road route reconstruction in plan

3.1 Rearranging Curves in Plan

When designing the route plan of the reconstructed road, it is necessary to strive to eliminate the unreasonable tortuosity of the road and to increase the radii of the curves if they do not meet the requirements of the standards, as well as to ensure visibility in sections where it is insufficient. To do this, compare the radii of the curves in the plan on the existing road with the design standards.

After analyzing the initial data, we conclude that none of the radii of curves of the existing road satisfy paragraph 4.22 [1]. Therefore, we will develop several options for the reconstruction of the existing road. An analysis of the route plan showed that the distances between the vertices of the rotation angles are sufficient, so it is possible to use compound curves in these conditions.

In this course project, 2 versions of the route plan were developed.

Option 1. The route leaves PK0 in the direction of CB 70 ° 52. " Throughout the route, the road changes direction 1 time. The length of all sections of the route along the existing earthen canvas is 269.16 meters. The length of the route was 490.27 meters.

Option 2. The route leaves PK0 in the direction of CB 70 ° 52 '. Throughout the route, the road changes direction 2 times. The length of all the section of the route along the existing earthen canvas is 326.22 meters. The length of the route was 491.55 m.

Based on the data of the length of use of the existing roadway and taking into account that the choice of route No. 1 option entails significantly large volumes of construction, since the road passes in the mountainous area, we accept option No. 2 for further design of the route.

To calculate the elements of the route plan, use the automated road design program "ROBUR." Based on the results of calculations, we compile a "List of rotation angles, straight lines and curves" (see Tables 3.2 and 3.3).

From the "Vedomosti" it can be seen that as a result of the reconstruction, the length of the section under consideration has decreased, the road is more smoothly inscribed in the surrounding landscape.

4.1 Summary Conclusions

In this chapter, a longitudinal profile of the category III highway was developed. The maximum longitudinal slope was 54.2% 0; the smallest radius of the concave vertical curve is 973 m.

Attention is also paid to the issue of drainage. For this, cuvettes were designed. Water is drained to reduced places where culverts are located (PK0 + 29, PK1 + 00, PK3 + 40)

The graphic appendix shows the drawing of the longitudinal profile of the highway.

7 Road Reconstruction Management Technology

The reconstruction of the highway involves the transfer of the road to a higher category, which causes its restructuring according to the norms of SNiP 2.05.0285 "Roads."

Work on the reconstruction of the road (roadway, road clothing) can be in a variety of ways. So, when restructuring the roadway, the following options are possible:

• Two-way widening;

• one-way widening with gripping part of the old;

• one-way widening;

• elevation of the roadbed;

• excavation device;

• construction of a new roadbed.

Analyzing the reconstruction project of the operational section along the highway, we identify that the above-mentioned options for restructuring the roadway are found on the road section under consideration.

In this course project, we will consider the technology of organizing reconstruction with two-sided widening of the roadway with strengthening of existing road clothing on the PK0 + 00 - 2 + 40, PK2 + 44- 4 + 91 section, the 55range of which is 326.22 m.

7.1 Supply of construction with road construction materials

In the vicinity of the reconstruction of the highway, the following road construction materials were explored:

1) sand quarry - at a distance of 12 km from the reconstruction site;

2) stone quarry - at a distance of 18 km from the reconstruction site;

3) soil quarry - at a distance of 8 km from the reconstruction site;

4) ABZ (CBZ) - at a distance of 8 km from the reconstruction site;

5) water for construction needs is delivered to a reservoir located 5 km from the reconstruction site.

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