Shaanxi-Beijing Four-line Yellow River Crossing Technology Research

The river crossing is an important problem for the whole project in the long distance pip eline project. How to use the technology of long distance transportation pipeline is the most i mportant work for long distance pipeline construction, especially for long distance and large diameter pipeline.the conventional non excavation method has been basically not applicable. In this paper, Shaanxi Beijing Four Pipeline the Yellow River crossing project as the research object, in-depth study of the Yellow River through the relevant key technologies, for the futu re similar long pipeline large river crossing project to provide useful experience. The main re search contents of this paper are:(1) According to the influence factors to the Shanxi Beijing line, four environmental im pact, on the three crossing position proposed are compared; combined with the shield, pipe ja cking, directional drilling, and then on the three crossing position after a comprehensive anal ysis, finally selected the the Yellow River crossing position.(2) Through the analysis of a variety of the Yellow River through the technical program, the choice of the specific cross program, summarizes the characteristics of different crossing scheme, applicable scope and conditions and its possible environmental impact. Finally, the directional drilling technology, which is widely used and developed in the field of non excav ation technology, is selected as the main research object.(3) Comparative analysis of multiple continuous directional drilling+intermediate foun dation pit and multi tube first directional drilling program, and choose to determine the pipeli ne crossing project as follows:multiple continuous directional drilling+deep foundation pit.(4) The calculation of the directional drilling through the curve, the calculation of the pu lling force, the design of the deep foundation pit and the way of its dewatering and the stabili ty of the pipe.(5) By checking the stiffness, strength, stability, stress and so on, it can meet the safety r equirements of pipeline.(6) To optimize the construction technology of directional drilling and foundation pit, an alyze the possible construction risks and put forward effective countermeasures.