Disease Analysis And Prevention Of Highway Roadbed In Qinghai Tibet Permafrost Region

With the development of economic construction, the road transport has become the major mode of transportation in Tibetan Plateau. However, the climate characteristic and geographical features of Tibetan Plateau, such as high altitude, low annual mean temperature, large temperature difference, frequent freezing, thawing cycles, and poor natural conditions, have adverse effect in the road construction. Diseases in permafrost regions are mainly concentrated in part of the roadbed, and highway subgrade disease is mainly due to the particularity of permafrost region and with the escalation of the global warming and human activities. The main diseases in a nonuniform deformation of subgrade, financial settlement, frost heaving and frost boiling, longitudinal cracks and loose damage phenomenon, various diseases seriously affected the highway traffic and the normal service life, and resulted in the enhancement of the maintenance cost.For the purpose of researching the impact of subgrade diseases to the stability, These factors make the roadbed are often in an unstable state, subgrade by the continuous action of heavy load traffic, fatigue failure, when the fatigue destruction intensifies, very easy to cause the instability of the subgrade, subgrade uneven deformation, financial failure precipitation, frost heave and frothing, longitudinal cracks and loose, and the western open increases the permafrost area highway overload, the highway subgrade damage is very serious. Therefore, it is necessary to study on the special area highway design and construction, and constantly improve the permafrost area highway operation service quality and road service life. To study all kinds of roadbed disease effect to the stability of the subgrade, this paper in the environmental characteristics of the frozen soil survey area, based on the characteristic of frozen soil, the permafrost subgrade produced reason and mechanism analysis research. Based on the analysis of the characteristics of the roadbed diseases in permafrost regions of the Qinghai Tibet highway, the causes and development of the disease are revealed, and the correlation between the various types of disease rate and the soil temperature, the type of ice and the height of the roadbed are analyzed.To deal with the subgrade diseases, this paper puts forward the design principles and methods of the roadbed in permafrost regions, and puts forward the corresponding measures to prevent and cure the disease.