Bored Pile Rotary Drilling Rig Construction And The Study Of Drill Bit In Haerbin-Dalian Passenger Dedicated Line

With the rapidly development of road and bridge construction, the city environmental protection requires more and more advanced technique and technology of foundation treatment construction. Due to the restriction of geological and environmental conditions, the traditional inverse circulation drilling technology is more and more unable to meet the demands of city foundation treatment construction and the project with large quantity and tight construction period. In recent years, with the successful application of the rotary drilling technology in many large projects, its efficiency,rapid,environmental-protection have been recognized by public. At present, common rotary drillers' structure and function are more or less the same. Whether the construction goes well or not is depends on the choice of drill bit. Choosing the right drill bit, we can usually get twice the result with half the effort.The article detailed describes the application of rotary drilling bit in the Ha'erbin-Dalian passenger dedicated line and the study of choosing the drill bit. It expounds rock's fragmentation mechanism under the static load and active load conditions, rotary excavation resistance theory and abrasion characteristics of drill bit during drilling process. Above all, the author also analysis the process that the rotary drill bit crushes rock at the bottom of well, and the power of rotary driller when digging the earth. All this content provides the theoretical basis for chosing the right rotary drill bit which is the most important factor during construction. At the end, the article classifies the rotary drill bit according to the structures, and answers the question on how to choose a right drill bit according to different stratum conditions.After choosing a drill bit, we need to judge the rationality of the choice by practical experience. The author integrates the geological drilling knowledge and proposes a way to estimate the rationality of chosing the drill bit as a discussional topic.