Akademik Veri Yönetim Sistemi
1 st International Conference on Advances in Engineering , Architecture, Science and Technology, Erzurum, Türkiye, 15 - 17 Aralık 2021, cilt.1, sa.156, ss.510
One of the soil improvement methods used in geotechnical applications today is grouting. Injection is a soil improvement method used during tunnel construction to stabilize soil and rocks, to fill existing cracks in rocks, to fix anchor rods and to prevent settlements on soils. In the areas where the injection process is applied, different formations (rock salt, etc.) can be encountered and the success of the process is affected by various parameters. One of these parameters is the setting time. For this reason, tunnels, anchorages, etc., which are hardly studied in the literature. The effects of the rock salt formation encountered in the applications on the setting time of the injection fluid were investigated.
In the study, 3-parameter, 4-level L16 experimental design was used according to the Taguchi Optimization Method. In the Taguchi Optimization Method, water/cement ratio (S/C), sand percentage (KY) and rock salt saturation percentage (KTDY) were selected as parameters and their levels were determined as 0,8-1,0-1,2-1,4, 0%-25%-50%-100% and 0%-25%-50%-100%, respectively. Setting time was determined by the Vicat Needle test.
According to the test results, the lowest setting time was 693 minutes, the water/cement ratio was 0.8 (1st level), the sand percentage was 25% (2nd level) and the saturation percentage with rock salt was 25% (2nd level). The highest setting time was determined in experiment with 2751 min, where S/C ratio was 1.4 (4th level), KY (0%) (1st level) and KTDY was 100% (4th level). In addition, S/N analyzes of each experiment were made by using the test results of the setting times. In the Taguchi Optimization Method, S/N values were calculated considering the situation where the shortest setting time is the best.
The lowest S/N value and the highest S/N value were obtained at the fourth and first levels of the S/C ratio as -68.79 and -56.81, respectively. In order to determine the effects of water/cement ratio, sand and rock salt saturation on the setting time, variance (ANOVA) analysis was performed and according to the results of the analysis, the most effective and least effective parameters on the setting time were determined as KTDY (45.91%), KY (%) 2.25) As a result, it was seen that the optimum mixing ratio for the setting time was 0.8, S/C ratio was 0.8, KY was 100%, and KTDY was 25%.
Keywords. Grout, rock salt, setting time, Taguchi Optimization Method