Self Drilling Hollow Bar：A Perfect Solution to Hole Collapsing When Supporting Loose & Broken Geology

Time:2022-01-06From:sinorock View:

In some construction projects, the geological conditions are not very suitable for drilling construction. However, if you want to reinforce the foundations of these buildings, we usually use pile to support. Pile support generally requires drilling. Then, the difficulty of drilling holes in construction is a very difficult problem.
When using ordinary hollow anchor rods for construction, it is usually necessary to drill with a drill rod first, then pull out the drill rod, insert the hollow anchor rod, and then grout through the hollow bar. Hole collapsing is very common in construction in relatively loose and broken geological structures that are severely affected by groundwater. The construction process of ordinary hollow anchor bars simply cannot be carried out in this kind of geology.

Self-drilling hollow bar is a new type of high-efficiency supporting material produced to solve this problem. The self-drilling anchor rod is mainly composed of drill bit, rod body, coupler, plate, nut and centralizer. All components are casted from steel or alloy steel. The surface of the rod body is continuous threaded to ensure the bonding of mortar and anchor rod. The centralizer is placed in the middle of each anchor rod to ensure the straightness of the hole and the axial force of the anchor rod. The backing plate and the nut are used to fix the end of the anchor rod and apply prestress. The drill rod is a hollow structure and the drill bit produces slurry. The holes are convenient for cleaning and grouting. Using self-drilling hollow anchor bars, drilling, grouting, and anchoring can be completed at one time, greatly improving construction efficiency, and the entire construction process does not need to use casing, and the grouting is full.

Most suitable for pebble layer geology and boulder layer geology, self-drilling hollow anchor rods can also be used in silty clay, sandy soil, miscellaneous fill, strong weathered rock and other geology. After the drilling is completed, pressure grouting can effectively strengthen the disturbed parts of the rock and soil around the drilling, and expand the diameter of the anchor solid. If there is a small amount of water seepage during the drilling process, it can also be blown into the hole with high pressure wind. The dry powder method forms a temporary wall around the borehole to reduce the collapse of holes.

t thread self drilling hollow bars of Sinorock

With the advantages that ordinary bolts do not have, when Self-drilling hollow bolts are drilling weathered rock layers, gravel layers, clay, sand, pebble soil, etc., the usual method is to add casing pipes during construction. To prevent hole collapse, casing can be omitted by using self-drilling hollow bolts. It is possible to inject pure cement slurry (non-clay layer) with a water-cement ratio of 0.45~0.6:1 while drilling to consolidate the hole wall and prevent the hole from collapsing. The biggest advantage of self-drilling hollow anchor rods is that drilling, anchoring and grouting are completed in one process, which simplifies the construction process.

Return The List