| The evaluation of soil and water conservation on highway project is one of the important contents of working out the soil and water conservation scheme, and it is the important limiting factor of approving and initiating a highway project too. The evaluation has not formed unified, normal evaluating methods and contents yet at present, this paper has carried on preliminary discussion to it. From the side of soil and water conservation, the paper discusses technology and method of evaluation from following respects:(1) the total arrangement as well as Comparison and selection of route schemes of the highway, the total arrangement evaluation analyzes that if lines (sites) accord with the restricted regulation or pay attention to soil and water conservation from macro-side. On this basis, selecting the schemes begins. Through the comparison of various kinds of common methods, The Analytic Hierarchy Process(AHP) is chosen that is relatively suitable for selecting the schemes, then the system of evaluation indexes is established. The paper chooses the representative factors that can reflect the soil erosion situation in road construction, assigned to different levels, determines evaluating index layer: project factor, geological factor, economic factor and landscape factor, and divides the index layer further, but the indexes need to adjust according to the concrete conditions while solving the practical problem. Using the AHP could turn different route schemes into amount, and then select out the optimum scheme.(2)main engineering's designs of the highway, it includes the allocation of earth-rock work, the site selection of borrow area of natural building material and dreg fields, project occupation of land, constructing organization and design, the measures which have function of soil and water conservation designed in the major project. Aimed at theirs own characteristics, the paper puts forward the focal points of evaluation, the principles that should be followed and possible questions, among them, scientific economical transportation distance is calculated in the allocation of earth-rock work which is on the basis of old formula, considering distances to the borrow area of natural building material and dreg fields and expenses on them to make the calculation more practical, and then optimize the balance of the allocation of earth-rock work. In addition, more accurate estimation method to the area of the temporary occupation of land is provided in favor of setting of the next safeguard.Finally, the section from Shanyin to Pinglu in Shanxi Province of the expressway from Rongcheng to Wuhai of National Expressway Net is taken as a example to be evaluated from the side of soil and water conservation, and has proved the feasibility and superiority of the evaluating methods. |
