Key Technologies Study On Xining-Huzhu First-Class Highway Capacity Expansion And Reconstruction Project

In recent years,with the rapid development of social economy and tourism in Qinghai Province,the traffic volume has increased rapidly,especially the "Xining-Huzhu First-Class Highway",which connects Xining,the capital city,and Huzhu County,the only Turkish autonomous county in the country.Driven by Qinghai's tourism industry,the traffic volume has grown rapidly,reaching a growth rate of 16%?35%in the past three years.It can be said that at the present stage,Qinghai is facing a dilemma of weak capacity of the existing first-class roads,low road service levels during the peak tourism season and peak periods,and unable to meet the demand.And to some extent has had a negative impact on the local economy and society.Therefore,in order to ease the growing traffic pressure,continue Bring into play the role of driving regional economic development,Xining-Huzhu First-Class highway expansion is imminent.At present,there are many engineering practices at home and abroad,especially at home and abroad for the reconstruction and extension of high grade highway,that is to say,the reconstruction and extension of expressway is no longer a technical blank.However,the highway reconstruction and extension should not only consider the requirements of site construction and meet the traffic and transportation functions,but also make scientific,reasonable and appropriate reconstruction and extension projects,that is,the reconstruction and extension projects should have their own characteristics.In order to adapt to the local human,geographical and social development needs,and to minimize the impact on the natural environment and public life,it is not scientific to directly apply the previous research results and implementation programs to this project.That means The "Xining-Huzhu First-Class Highway Capacity Expansion and Reconstruction Project" also faces technical problems such as roadbed reconstruction and extension scheme,pavement splicing technology,and transportation organization in the peak period of tourism,so it is very necessary to do relevant research and discussion on it.In this paper,the key technologies of,Xining-Huzhu First-Class Highway Capacity Expansion and Reconstruction Project" are studied as follows:Technology of rebuilding and extending subgrade and pavement.? New subgrade and pavement structure after splicing.The total width of roadbed is 33.5 m.The top,middle,lower layer,seal layer,base course and bottom base are respectively made of AC-13C SBS modified asphalt fine grained asphalt concrete,AC-20C SBS modified asphalt medium grained asphalt concrete,ATB-25 's dense gradation asphalt macadam,asphalt synchronous macadam,cement dosage 5%and 3.5%cement stabilized macadam paving,the thickness is 4cm?5cm?8 cm,1 cm?,18 cm and 30 cm,respectively.?Form and scheme of pavement widening.As far as possible,both sides of the widening mode,for the conditions of limited local sections of the use of unilateral widening mode.? The pavement reinforcement structure of the reconstruction and extension section.The pavement structure is composed of AC-13C SBS modified asphalt fine grained asphalt concrete,AC-20C SBS modified asphalt medium grained asphalt concrete and ATB-25 dense graded asphalt macadam with thickness of 4 cm,respectively.5cm and 15cm.Subgrade splicing and subgrade construction control standard.? Subgrade splicing.The transverse connection between the old and new pavement is mainly carried out by digging the slope of the original subgrade into steps,laying geotechnical lattices on the top surface of the roadbed and the top surface of the following two or three steps,removing all the original hard kerbs and excavating them into steps,and so on.? Subgrade construction control standard.The differential settlement should be less than 1.7 cm after construction.Crack prevention technology for pavement splicing.In view of the characteristics of diversified splicing in the reconstruction and extension of the project,the comprehensive crack prevention measures for the base course and the surface layer are put forward.For the optimum selection of anti-crack material,the anti-cracking material,economic and construction aspects are more balanced,can be used as pavement anti-cracking material.In order to improve the ability of anti-reflection crack of asphalt pavement,the pavement layer thickness is added to improve the anti-reflective crack of asphalt pavement.Traffic organization for reconstruction and extension projects.The traffic organization scheme should follow the principle of no interruption and little influence.It is necessary to consider the reaction of the traffic organization scheme to the construction scheme and the design scheme during the construction period,and to formulate the feasible traffic organization plan according to the overall project plan.To sum up,through this research,we can promote the smooth implementation and development of Xining to Mutual Aid Grade one Highway expansion and Reconstruction Project to a certain extent,and then achieve its functional purpose.