Difficult geological conditions of the mountainous Crimea and the southern coast lead to numerical landslides in these areas. The Road Service in the Autonomous Republic of Crimea, together with the Yalta Engineering-Geological and Hydrological Party of the State Geological Service of Ukraine, continuously monitors landslide areas, and compiled an inventory of landslides that destroy highways. According to the latest data, 1576 landslides are observed in Crimea, of which 250 are destroying highways, 79 landslides are in an active state. The total length of road sections that pass through the landslide body is 37.2 km.
The Roads Service in the Autonomous Republic of Crimea has developed a Program of Work to Strengthen Landslide Areas for Engineering Protection of Highways with the involvement of research design institutes and the use of modern building materials and new technologies, and outlined priority measures for the repair of emergency road sections.
According to experts, each landslide has its own characteristics and needs an individual approach. To fix each part of the landslide, a set of measures is being developed, which may consist of the following parts:
- arrangement of drainage structures;
- construction of gabions;
- construction of bored piles;
- arrangement of grillages;
- construction of flyovers;
- construction of retaining walls;
- anchoring.
Landslide elimination is a lengthy process that takes an average of 6 to 10 months. Experience shows that preventing landslides on roads is much cheaper than eliminating the consequences of increased landslides, because this leads not only to a multiple increase in construction costs, but also to economic losses as a result of traffic restrictions.
Previously, anti-landslide measures were carried out by the method of rope-percussion drilling using the UKS-112, UKS-30 units, which caused pollution of the environment with sludge and was accompanied by micro-earthquakes, which increased the risk of landslide activation. Since 2007, the method of dry rotary drilling has been used, which has increased productivity by five times, shortened construction time, and eliminated negative impact on the environment. The method fully meets all environmental requirements, which is especially important in the conditions of the resort and conservation area.
For the arrangement of bored piles with a diameter of 420-1650 mm and a drilling depth of up to 42 m, highly productive drilling complexes of the Yuntan and Bauer firms are used. Quality control is carried out using control and measuring equipment installed on these complexes.
When anti-landslide works on sections of the highway Kharkiv-Simferopol-Alushta-Yalta km 708 + 200; 708 + 580 - 708 + 720; 708 + 720-709 + 135, Yalta-Sevastopol highway, km 39, anchoring of Bayer - four-rope seven-wire in a corrugated pipe in the amount of 41 units with a depth of 21-35 m was carried out.
During anti-landslide works, dry rotary drilling was used to arrange piles up to 36 m deep - the total volume of work performed in 2007-2008 at four sites was 15,275 m3.
Bored pile technology provides the following benefits:
- Possibility of obtaining high bearing capacity of finished piles.
- High-quality imported equipment with low noise level (environmental requirements for noise pollution).
- Absence of vibrations and shock influences during piling, which makes it possible to work in shear conditions.
- The drilling rig is completely autonomous and works only in tandem with a concrete mixer truck, which makes it possible to effectively organize the construction site.
- Guaranteed verticality of piles and high accuracy of their arrangement.
- Possibility of operation of equipment from the mark of the day surface or in a foundation pit with appropriate preparation of its base.
- High quality of the formation of the concrete body of the pile due to the concreting of the pile in the casing and vibration in the process of pulling the casing.
- No need to equip sludge storages; the soil that is taken out is environmentally friendly and does not have a negative impact on the environment.
To equip pipes in embankments, an environmentally friendly resource-saving horizontal drilling technology is used, which is implemented using special equipment, eliminates the need to open the embankment without interrupting traffic, which in turn reduces the cost of work several times and shortens the construction time. For the first time in Crimea, at km 708 + 585 and Kharkiv-Simferopol-Alushta-Yalta, the technology of horizontal drilling - "Puncture" of large diameter 1020 mm was used to equip pipes with a length of 84 linear meters in the embankment.
