Original Title: Construction Method Sharing of Rotary Drilling Rig Roller Bit Drilling Rock-socketed Pile I. Characteristics of construction method 1. The machines and tools used in the construction method are compared with the original steel shot The machines and tools required for alloy drilling are basically the same, except that the rock breaking tool, the drill bit, is replaced and a weighting device is added, which can be popularized and used in general rock-socketed pile construction sites. 2. The operation is simple and convenient Wide adaptability. It can be drilled without circulation or reverse circulation,dth hammer bit, and the production workers can master the operation technology after short-term training. 3. The crushed rock of this construction method is uniform. High efficiency, low construction cost relative to alloy drilling,rock drilling tools, and good pore-forming quality. Duff cone drill II. Scope of application This construction method is applicable to the construction of rock-socketed pile holes with a pile diameter of less than 1,500mm and a relatively flat rock surface. III. Process principle 1. When the cone foot works at the bottom of the hole, it revolves around the drill string. It also rotates around the mandrel of the palm of the bit, and its rotation is carried out in the form of rolling, Tapered Rock Bit ,dth drilling hammer, so the running resistance is small, so it can bear a large bit pressure. 2. When the roller bit contacts with the rock at the bottom of the hole, The contact area between the alloy insert on the palm and the rock is small (as a fulcrum contact), so it is easy to obtain a higher unit axial pressure to crush the rock. 3. When the cone rotates at the bottom of the hole In addition to the axial pressure of the drill string, it is also subjected to the impact load caused by the change of the height of the cone center during rotation, which improves the rock breaking effect. 4. When the palm insert is rolling at the bottom of the hole, The rock crushing is carried out alternately, the working time of each time is short, and the wear rate is low, which is beneficial to improving the service life of the bit. Duff cone drill IV. Process flow 1. Alloy drill bit shall be used for pile hole opening and soil covering construction. The construction shall be carried out according to the construction procedure of rotary bored cast-in-place pile. 2. When the alloy drill bit is applied to the strongly weathered rock formation or hard rock formation The drill can be lifted and replaced with a suitable roller bit to drill to the depth required by the design. 3. When the construction reaches the required depth, the rock debris of the bedrock is fished out from the flushing fluid returned from the pile orifice. After the completion of the hole is approved by the on-site supervision personnel, it can be turned to hole cleaning, steel cage lowering, tremie lowering, secondary hole cleaning and underwater concrete pouring to form piles. 4. After the roller bit is lifted ? The rock debris and sediment in the barrel should be removed in time,mining drill bit, and the wear of the cone foot, support point and flange should be checked. If there is any damage, it should be repaired in time for use. Return to Sohu to see more Responsible Editor:. wt-dthtools.com