Research On Preventive Measures Against Damage To Underground Pipeline In The Process Of Directional Drilling/Guided Boring And The Referred Technology

In the recent ten years, directional drilling/ guided boring technology being used to lay different kinds of underground pipelines has been greatly applied. Nevertheless, it does not mean that we can guarantee the successful application of this technology into each construction, since both subjective factors and objective causes contribute to the ultimate result.Currently, research on directional drilling/ guided boring technology focuses mainly on the specific and detailed construction engineering, equipment, and the compounding of concrete, etc. whereas the research on the preventive measures for underground pipeline is still not adequate.In accordance with the related standards and norms existing in the pipeline- laying industries, in light of the principles of directional drilling/ guided boring trenchless technology, and based on the author's own experience, the paper presents us the research on the preventive measures against damage to the underground pipelines in the process of directional drilling/guided boring.To begin with, the paper classifies the underground pipes, analyzes the construction environment of horizontal directional drilling/guided boring according to the influencing factors as well as the safety margin for laying the pipes, and it further points out the key points in the geotechnical investigation and diction for the trenchless projects.Secondly, the paper describes the basic parameters of designing the bore path according to the general principles. It then give details to the main content of designing the bore path of directional drilling/guided boring, conducts the optimum calculation of the guide bit and guide angle, and makes the optimum design for the enlarging diameter in the process of enlarging a hole. It continues to refer to the preventive measures against damage to the underground pipelines and the referred technology, based on the different features of the existed pipelines and that of those being laid, and also based on the extent to which the construction environment can be influenced. In the end, by citing some successful cases, the paper places great emphasis on the significance of constructing in a scientific way as the implementation procedure prescribes.