Study On Subgrade Widening Technical Design And Construction Technology Of China- Nepal Highway Reconstruction Works In Tibet

With the rapid development of economy.the regional affiliation need is frequent day after day, volume of road traffic explosive quickly.A considerable number of expressways in service are no longer satisfy the need for both increasing traffic volums and social progress,it is confinement the development of economy.Thus more and more highways are pending to be reconstructed or widened.It′s the basis of China-Nepal road extension project ,through scene inspection and testing ,combining with the relevant existing standard ,Construst technique and the Engineering Properties of the old road reconstruction are researched by methods of in-site test ,numerical simulation and theoretical analysis in this paper. Researched results on the road extension project has important theoretical and practical significance improving the quality and life of the project. The main work and conclusions can be given as follows:⑴Based on comprehensive analysis of the situation on the widening of road at home and abroad ,the major problems existing on the widening of road are preliminary analysed.⑵obtaining damage model and damage mechanism in analysising reconstruction and extension project. The fininte element method using Mohr-Coulomb elstic-plastic model is applied to the analysis of interaction mechanism between the old and new embankments in the expressway widening on soft soils during the construction and operation .⑶Considered the factor of difference broaden width ,broaden height and different broaden forms, simultaneously considered the disturbance of construction,the ground water transfusion as well as the transportation load's influence ,researched the changing law of engineering properties of ground under old and new embankments, and got the influence law of the factor .⑷On the base of material investigation, discussed the method of the ground treatment,selected of packing loaded stock,compaction method and machines of the project.discussed construst technique in subgrade of the road .⑸On the basis of failure mechanism of joint of the old and new embankment ,the treatment measures of the joint and the effect of improvement are studied .