Prime Minister Sapar Isakov instructed the State Ecological and Technical Inspectorate to create a commission with the involvement of independent experts thoroughly to study the causes of the deterioration of the road pavement of Bishkek-Naryn-Torugart road.
According to the Ministry of Transport, rehabilitation of the road section from the 439th to 479th km was carried out in 2010-2013 at the expense of investment funds of the Asian Development Bank. In 2014, after the warranty period, the road section was put into operation.
After the winter frosts of 2012/2013 season, longitudinal cracks with a width of up to 2-3 cm appeared on the new asphalt-concrete cover. An international expert was invited for a detailed examination of the cracking. It was found out that the crack extends to the entire depth of the pit and goes even deeper, to the depth of freezing.
«According to the conclusion of the international expert, the main reason for the cracking is frost heaving associated with weak basic soils at the base of the pavement. Taking into account the fact that the depth of freezing in the region reaches 1.8-2.0 m and the total thickness of the pavement with the working layer of the roadbed is 77 cm, it is not possible to exclude the effect of frost heaving on the construction of pavement. Removal of all unsuitable soil to the depth of freezing or erection of a mound of more than 1.5 m would entail a significant increase in the cost of work, which did not allow the project budget,» the press service of the government said.
The road runs in the area of severe climatic conditions with sharp changes in air temperature in the winter (from +10 to −40 at night). Cracks are flooded after thawing of soils in the spring-summer period.
