CAJ | 학술논문

扩孔器是定向穿越扩孔钻进阶段进行岩土切削的主要工具,合理的结构设计是提高扩孔时效、降低工程复杂问题出现几率的主要手段,且由于扩孔阶段是决定定向穿越工程工期的最主要阶段,因此,对扩孔器切削齿的切削效率进行深入研究是非常必要的.从单齿正交切削岩土的机制入手,综合考虑岩土与切削齿面之间的接触摩擦及岩土剪切区的剪切作用,分析了单齿正交切削岩土的力学特征,基于能够考虑中间主应力对岩土破坏影响的Drucker-Prager强度准则,推导了单齿正交切削岩土的主切削力与主切削力矩计算公式;在利用有限元计算程序对所推导公式进行验证的基础上,优选了剪切角计算模型,获得了不同岩土材料时的主切削力解析解,并分析了不同齿前角对主切削力的影响规律,从而获得单齿正交切削岩土的最优齿前角,为进一步研究扩孔器整体结构设计并针对不同岩土介质设计出适应性更强的扩孔器结构奠定基础.
확공기시정향천월확공찬진계단진행암토절삭적주요공구,합리적결구설계시제고확공시효、강저공정복잡문제출현궤솔적주요수단,차유우확공계단시결정정향천월공정공기적최주요계단,인차,대확공기절삭치적절삭효솔진행심입연구시비상필요적.종단치정교절삭암토적궤제입수,종합고필암토여절삭치면지간적접촉마찰급암토전절구적전절작용,분석료단치정교절삭암토적역학특정,기우능구고필중간주응력대암토파배영향적Drucker-Prager강도준칙,추도료단치정교절삭암토적주절삭력여주절삭력구계산공식;재이용유한원계산정서대소추도공식진행험증적기출상,우선료전절각계산모형,획득료불동암토재료시적주절삭력해석해,병분석료불동치전각대주절삭력적영향규률,종이획득단치정교절삭암토적최우치전각,위진일보연구확공기정체결구설계병침대불동암토개질설계출괄응성경강적확공기결구전정기출.
@@@@Reamers have been the major implements used to enlarge the hole size in reaming stage of horizontal directional drilling (HDD). The choice of its available structural design becomes critical to maximize the rate of penetration and minimize the tripping time;thereby decreasing the cost of operations and the risk of experiencing stability problems. Moreover, because the duration period of a HDD project is largely dependant on the reaming stage;it is crucial to study the reaming efficiency by use of the appropriate operating conditions (cutting angle and depth). The reaming efficiency of reamer is analyzed based on the development of a 3D analytical cutting force model of soil orthogonal cutting under a single reamer cutter. Focusing on the soil orthogonal cutting mechanism under a single reamer cutter, the interaction and friction between soil and cutter and the shear action of 3D shear zone are comprehensively considered, consequently the mechanical properties are given. Based on these analyses and using the Drucker-Prager criterion given a weight to the intermediate principal stress, the analytical models are proposed. In addition, this paper presents 3D FEM simulations for the analysis of soil orthogonal cutting under a single reamer cutter. The subject has been covered in two parts. Part one deals with the verification of the analytical cutting force model, the other focuses on the assessment and selection of the criterions of shear angle. The analytical cutting force model presented provides the capability to evaluate cutter loading for utilization of a single cutter with different rake angles to cut soils, and to plot the effect of change in the rake angle. Finally, the optimum rake angle of single reamer cutter was obtained. The results of this analysis can be integrated to study reamer performance. It can also provide a guideline to the application and design of the reamer assembly for various soils.