Study And Analysis Of Effects On Appropriate Roadbed Height In Desert Areas

China is one of seriously deserted countries in the world. China has a relatively large desert area and its distribution is vast, whereas most of deserts mainly locate in the northwest areas , such as Inner Mongolia and Xin Jiang , etc. The economy and culture in these areas is backward compared with the east coastal areas , be cause of history .geography location and climate etc , The backward highway trasportation condition in the west has been an obstacle to the economic development . Nowadays it is a historic period for the west development , and the construction of highways in these areas is seriously required . The highway research in desert areas has been continuous from the state' s establishment , but the research for resolving the harm of windblown sand is superficial sand burry and wind erosion are harmful to highways in desert areas under the impact of geography and landfeature , plantation and geology , sand plains and wind velocity intensity , etc . The main purpose of this discussion is to determine the appropriate roadbed earthfill height according to the degree of sandburry , windblown sand drift test , wind tunnel test , windbed stability , road economy and traffic accident analysis . The appropriate roadbed earthfill height is one of vital factors in preventing highways from the harm of sand . Meanwhile '鈥? it is also the key factor to improve the highway grade in these areas . The sand harm usually happens and the roadbed is obviously influenced by the sand foundation stability condition and the groundwater if the roadbed earthfill height is low . On the contrary , the wind erosion usually happens if the height is high . Because of the high roadbed and the problem of rock and soil stability , the engineering cost will be brought up correspondingly . Therefore , developing the research of this discussion is the inevitable requirement of highway engineerings in desert areas , whose social and economic meaning is significant .The research test of this discussion as follows : making investigation and research to overseas related materials ; make investigation to built highways in desert areas ,dozens of routes and nearly 100 road sections have been surveyed , among them two highways have been taken as the chiefinvestigation objects , they are '210 national highways - first grade highways from bao tou to Dong sheng 'and 'the section of Nei Meng A La Shan Meng S307 from Shang De to Meng Gen'; the relationship between windblown sand drift and the roadred height wind tunnel test ;make investigation to the tested road sections and subengineerings then make statistics and study according to the test outcome ; the stability analysis of different roadbed height; the analysis of roadbed economy.A recommend value of appropriate roadbed height is put forward according to the sand dune type and the highway grade , make investigation to the sand harm and other problems of built highways in desert areas gathering the related materials of present day highways , and then make comprehensive and systematic statistics to related data and racious factors which affect the roadbed height; analy the suitable roadbed height for the windblown sand drift passes through smoothly according to the open country windblown sand field test; test and verify the outcome according to indoor wind tunnel test; finally a appropriate recommend roadbed height value will be put forward for different grade highways in different areas , which is according to the analysis of roadbed stability the roadbed height economic analysis and different use requirement to different grade highways.