【摘要】 在滑坡防治大直径桩孔施工过程中,快速钻进是治理成功的关键。因此选用合适的钻进机具与工艺极其重要,而气动潜孔锤因钻进效率高被广泛应用。气动潜孔锤钻进过程中,通过钻头底部球齿对岩石进行切削,达到高效碎岩目的,但球齿在破碎岩石过程中若冲击功选用不恰当,会导致能量损耗增大、球齿磨损较快、钻进效率低等问题,因此选用合适的冲击功进行碎岩具有重要意义。本文采用ABAQUS软件对单个球齿冲击岩石的过程进行了数值模拟,并进行了冲锤自由落体冲击实验,分析?19 mm的球齿在不同冲击功条件下的碎岩机理、破碎面积的变化规律。结果表明球齿碎岩机理分为3个阶段:弹性变形、压裂、体积破碎,且当球齿以30 J冲击功钻进花岗岩时,可有效降低能量损耗与提高碎岩效率。更多还原

【Abstract】 In the process of large diameter pile hole construction for landslide treatment,rapid drilling is the key to success. Therefore,the selection of appropriate drilling tools and technology is extremely important,and the pneumatic DTH hammer is widely used because of high drilling efficiency. With the pneumatic DTH hammer drilling process,the spherical teeth on the bottom of the bit break rocks to achieve high drilling efficiency;however,inappropriate selection of impact energy for the spherical teeth can lead to increased energy loss,quick tooth wear and low drilling efficiency.Appropriate selection of impact energy is of great significance to rock fragmentation. In this paper,ABAQUS software is used to simulate the rock impact process by a single spherical tooth,and the free-fall impact experiment is carried out on the impact hammer to analyze the rock fragmentation mechanism of a 19 mm diameter spherical tooth by at different impact energy,together with the change pattern of the broken area. The results show that the rock crushing mechanism can be divided into three stages:elastic deformation,fracturing and volume crushing. When the spherical teeth drills granite at 30 J impact energy,energy loss can be effectively reduced and rock crushing efficiency can be improved.更多还原