The concrete construction process of bored pile engineering is mostly underwater, and the whole construction process can not be observed. Therefore, any link problems in the construction process will have a direct impact on the quality of the whole project. In view of the large amount of slurry produced in bored pile engineering, the slurry pollution concentration is high and the composition is complex, which is quite serious to the natural environmental pollution and human health hazards. Moreover, if the slurry of bored piles is not properly treated, it will cause huge economic costs to the investors of the project. In view of the above reasons, the requirements of slurry treatment for bored pile engineering are summarized as follows:
1) Requirements of soil-carrying and slag-discharging: One of the basic requirements of mud treatment in bored pile driving engineering is to bring the broken rock and soil debris out of the drill hole so as to maintain the continuous process of drilling. When the mud circulation is temporarily interrupted, the mud can suspend the drill debris, so as not to sink quickly and prevent the risk of sand sticking to the drill. In positive circulation drilling, mud suspends drilling cuttings and discharges them.
2) Requirements for cleaning boreholes: In the construction of bored cast-in-place piles, boreholes must be cleaned immediately after drilling. The purpose of clearing boreholes is to prevent gravel and sand particles from precipitating in the boreholes, so as to exceed the prescribed sedimentation thickness. In the process of drilling, the mud takes out the drilling cuttings and circulates to flush, which has the function of cooling and lubricating the bit. It also reduces the repeated fragmentation process of drill bits, thus reducing the wear of drill bits.