Confirmation of main factors affecting pulling force of self drilling anchor
On the basis of affinity map analysis, the main factors that affect the pulling force of self drilling anchor are confirmed by the analysis of affinity diagram.
1) the drilling hole forming technology is not reasonable
The first is the improper selection of drilling methods, drilling using ordinary geological drilling rig, drilling quality can not be guaranteed; the second is the improper selection of technical parameters for drilling speed, chase efficiency, jumbolter drilling speed too fast, so that the hole wall is not smooth, rock fall, reducing the bond strength between grout and the soil.
2) the choice of cleaning method is not proper
First, the wind pressure of used clear hole machinery is small, the hole can only be out of small debris when clearing holes, and a larger debris can not be washed away, which affect the quality of grouting; second ,it is not familiar with the standard of clear hole. As there is no standard for clearing holes in advance, the management does not know what standards are required to meet the requirements.
3) the batching process control is not strict
The batching process is not clear, and the material is not measured, the error is large, which affect the strength of grouting body.
4) the grouting process control is improper
Construction personnel quality consciousness is weak, in order to ensure grouting without blocking the pipe, mixing cement slurry when the water to cement ratio is too large, cement slurry mixing time is short, pressure gauge failure, grouting pressure control is improper, and some hole grouting is not full.
5) the quality awareness of operators is poor and the implementation of construction management system is not enough
Because the field lacks the strict of self drilling bolt construction management system or the implementation dynamics is insufficient, the feeding personnel does not measure according to the request, only by the experience estimate discharge, the error is big, the grouting process does not conform to the design request.
