## 2 Materials and Methods
### Experimental Design  
The anchoring mechanism of tension-compression composite anchors displays notable distinctions when contrasted with that of traditional anchors. Currently, there is limited existing research in this field, and there is an urgent requirement for thorough investigation. To gain a comprehensive understanding of the load-carrying characteristics of the new tension-compression-dispersed composite anchors and their distinctions from traditional tension-only and compression-only anchors, full-scale field tests were performed. Traditional tension anchors were employed as a control group, and a thorough analysis and examination were conducted on the anchoring performance of the tension-compression-dispersed composite anchors. To enable a comprehensive comparison, the experiment involved the design of four anchor groups. The first group consisted of composite anchors, while the second to fourth groups were tension anchors. The composite anchor had an effective anchorage length of 3 m, with each tension section measuring 0.75 m in length and the compressive section spanning 1.5 m. To create a non-adhesive section (compressive section), a bearing plate and a 1.5 m long steel casing were welded at the 2.25 m mark on the anchor body. The bearing plate, with a thickness of 5 cm and a diameter of 19 cm (smaller than the anchor hole diameter to ensure smooth insertion), had a hole shape formed by two round tables meeting on the top surface to ensure strong welding seams. Figure 2: The structure of the tension–compression-dispersed composite anchor: (**a**) schematic representation of the rock and anchor structure; (**b**) composite anchor structure. Where symbol # represents the number of the tension anchoring section. The steel casing used was a 6 cm diameter steel pipe with a wall thickness of 2.5 mm. In the experimental procedure, the drilling sites, hole diameters, and depths were determined based on the geological conditions obtained from survey data. After drilling the anchor holes, the anchors were positioned in the holes according to pre-established locations with the assistance of a crane. Following this, grouting was performed using a cement grout mixture. Ordinary Portland cement was used, and a rust inhibitor for steel reinforcement was included. The grouting process was conducted iteratively, with the addition of fresh grout when the preceding grout had settled, until the entire anchor hole was entirely filled with grout. During loading, both tension sections and the compressive section of the anchor were simultaneously subjected to the applied load, working together to resist deformation. The performance of the composite anchor was evaluated by comparing it with tension anchors of different lengths, with the anchorage length of the composite anchor considered as an equivalent alternative to that of the tension anchor. Each group included three parallel samples, resulting in a total of 12 anchors. The parameters of the anti-floating anchors are presented in Table 2. All anchor holes had a diameter of 200 mm and were spaced 3 m apart. These holes were formed using an anchor-forming machine. Figure 3 illustrates the arrangement and physical depiction of the anti-floating anchors on the construction site. The anchor body of the floating anchors was constructed using a 40 mm diameter rebar (HRB 400) with a modulus of elasticity of 200 GPa, a density of 7850 kg.m\({}^{-3}\), and a Poisson's ratio of 0.3. After grouting, the floating anchors were cured for 28 days before conducting field load tests. The loading monitoring device utilized in the experiment is depicted in Figure 4. The test program consists of a graded load, where a load of 85 knuckles is applied at each stage and maintained for a stable period of 5 min. The loading process employed a 100 T automatic oil pump and a hollow jack, with the loading value read using an intelligent pressure gauge. Tests of distance were conducted using a 100 mm mechanical percentage meter, placed on both sides of the anchor head.