Study On The Stability Of Subgrade Side Slope Along Dongshanpo~Maojiagou Section (within Ningxia Province) Of Qindao~Lanzhou Highway

As the national capital in recent years greater efforts devoted to the rapidpace of highway construction,road construction and slope control in the face ofrock and soil slope stability is also a corresponding increase.Slope in thehigh-grade highway construction and operation process,the slope instabilityphenomenon has occurred from time to time,and once slope instability,and itsoften disastrous consequences. Therefore,high-grade highway slope stabilityanalysis and treatment technology research,development of effective protectivemeasures,has a very important theoretical and practical significance of theproject.Based on the data collected from the investigation into the scope， landarea， geology， climate and meteorology and so on of Liupanshan dank area，this thesis discloses that this area is located within three areas of Ningxia:semi-humid area， semi-dry area and dry area. The detailed investigation iscarried out to the diseases of existing road in the dank area， mainly including the settlement of embankment side slope， debris avalanche of subgrade sideslope， slide of subgrade side slope， sliding of subgrade along the mountain，mud-rock flow， salivary flow ice， etc. The idea that there are two unfavorableseasons for the highway construction in dank area so the construction should bearranged from April to June each year is put forward and reliability analyses ofthe high side slope in the dank area should be carried out on the sliding forms isdemonstrated. Through the analyses on inner and exterior factors of the highembankment， checking calculation and analysis for stability of specialsubgrade side slope is determined. The Bishop Method is adopted to calculatethe stability of high embankment side slope， and the method of circle arccracks is adopted to calculate the stability of high-cutting side slope. Therelationship between stability coefficients and cohesion， inner fractional angle，earth fill height， side slope grade is analyzed， and accordingly the structuremode of high embankment and high-cutting side slope is put forward. Throughthe above study， this thesis aims to provide beneficial references for theupcoming highway construction project of49-km Dongshanpo~Maojiagousection of Qindao~Lanzhou highway which will pass the dank area of Ningxia so as to promote the advance of Ningxia’s highway construction.