Research On Subgrade Construction Quality Control Based On Prevention Of Lalin Railway Subgrade Frost Diseases

Lhasa to Linzhi section of Sichuan to Tibet railway is located in the southeast part of the Qinghai Tibet Plateau in permafrost regions with an altitude of 3200 m to 3700 m.Railway roadbed can be divided into frost damage,roadbed subsidence,extrusion deformation,slope collapse and other diseases in accordance with forms.And subgrade frost damage is the most widely and the most common disease in cold area,especially in permafrost region distribution of railway line,which poses a serious threat to the normal operation and safety of railway.Therefore,the adverse effects of frost damage on subgrade must be considered in Lalin railway subgrade construction process,and effective measures must be taken to deal with it.This paper first discussed the different types and causes of subgrade frost damage,the influencing factors of subgrade frost damage were analyzed,and the subgrade frost damage control measures were classified and summarized;Lalin railway subgrade filling construction process were summarized.Focused on the subgrade frost damage of Lalin railway,filling improvement,artificial saline method,and compacted sand pile in the reinforcement measures were taken for subgrade construction quality control.After the treatment subgrade settlement was observed.which showed that the sand pile,artificial saline method,improved soil measures for reducing permafrost subgrade settlement had good treatment effect,effectively reducing the adverse effects of cold damage on subgrade.