Factors That Affect the Quality of Self-drilling Anchor Bolt System

Time:2022-03-29From:sinorock View:

Self-drilling anchor bolts are mainly used in foundation pit support engineering, foundation reinforcement engineering, slope engineering, tunnel advanced support engineering, etc. From the formulation of the construction plan in the early stage to the construction, professional design is required to achieve the ideal anchorage Effect. At present, the quality of self-drilling grouting bolts on the market is uneven. Below, Sinorock will introduce how to control the quality of self-drilling grouting bolts.
/d/pic/self-drilling-anchor-bolt-system-quality.jpg

/d/pic/self-drilling-anchor-bolt-system-quality.jpg

Factors affecting the quality of self-drilling anchor bolts

1. Quality inspection standards

In order to ensure the product quality of self-drilling grouting bolts, meet customer requirements, and make products competitive, good quality inspection standards are the foundation. Sinorock products have ISO9001 quality system certification, and have obtained a sales pass to enter the EU market, which conforms to international standards.

2. Raw material suppliers

The quality of self-drilling grouting bolts needs to be taken from the source. Most of the domestic manufacturers of self-drilling grouting bolts do not have strict management procedures for raw material suppliers. Sinorock will comprehensively evaluate the supplier's company qualification, production capacity and quality control level, and conduct product quality verification through the three links of first article inspection, small batch trial production, and batch supply, and select good suppliers.

3. Production process

The production process of self-drilling grouting bolts also has a great impact on product quality. In the process of processing, it is necessary to fully control the product quality to ensure that the product meets the technical requirements. Sinorock will conduct performance tests on different batches of hollow bolt bodies, connecting sleeves and nuts, and adopt a "three-inspection system", namely self-inspection, mutual inspection, and special inspection, and strictly control the production quality.
/d/pic/self-drilling-anchor-bolt-system-quality.jpg

Self-drilling anchor bolt anchoring quality

1. Repeated grouting technology

In the anchoring construction, two important factors that determine the quality of the anchor are drilling depth and grouting strength. If the grouting fails to meet the requirements, the grout cannot be firmly bonded to the bolt body, nor can it fill the cracks in the rock and soil mass well, and the anchoring effect is greatly reduced. Grouting in two or more times during drilling construction can achieve better anchoring effect.

The first grouting and drilling are carried out at the same time. The grout is relatively thin (the water-cement ratio is about 1:1), which can not only play the role of slag discharge, but also effectively fill the cracks in the rock and soil mass and consolidate the fractured rock mass. . In the second grouting, after drilling to the design required depth, the slurry is thicker (water-cement ratio is about 0.45~0.6:1). The pressure grouting method is adopted for the two grouting, which can fill the borehole and rock mass fracture more fully with the grout.

2. The size of the anchor

The generation of the anchoring force of the self-drilling hollow bolt mainly depends on the friction between the self-drilling hollow bolt and the anchor, as well as the friction between the anchor and the rock and soil around the borehole. Self-drilling hollow bolts need to increase the diameter of the anchor body through slurry wrapping, thereby generating greater anchoring force.
/d/pic/self-drilling-anchor-bolt-system-quality

/d/pic/self-drilling-anchor-bolt-system-quality

The above is the explanation of the quality control of the self-drilling grouting bolt. In the self-drilling anchoring system, the role of the centralizer and the connecting sleeve cannot be ignored. The connecting sleeve needs to be as strong as the bolt. The surrounding thickness is uniform to strengthen the anchoring effect.

Return The List