No abstract

The objective of this paper is to investigate the effect of nano-calcined clay (NCC) and nano-lime (NL) on some engineering properties of the expansive clayey soil. Three soil samples quarried from three different sites in the south of Syria have been investigated. They were thermally treated up to three different levels (450, 650 and 850°C) for 3 hours. Then, they were ground to have a particle size of less than 100 nano-meter. Three replacement levels of NCC were used, i.e. 0%, 1% and 2%. XRD technique has been employed to detect the phases occurring in the clayey samples before and after the thermal treatment. Pozzolanic activity of the calcined clayey soil has been studied using the modified Chapelle test. Atterberg limits, compaction, free swell, swelling pressure, linear shrinkage, shear strength and CBR have particularly been investigated. Test results revealed the positive effect of NCC. Plasticity index (PI) was reduced by more than 50% when 2% NCC was added to the natural soil. In addition, 0.6% NL was added to further investigate the combined effect of NL and NCC on the properties of the clayey soil. All investigated properties were significantly improved when NCC and NL were added together, i.e. swelling pressure and linear shrinkage values were reduced to less than 15% when compared with those of the natural soil.

This corrigendum corrects the following error. There was a missing reference in the reference list. This has been included as reference 18. [18] Al-Swaidani A M, Hammoud I., al-Ghuraibi I and Mezyab A 2019 Nanocalcined clay and nanolime as stabilizing agents for expansive clayey soil: Some geotechnical properties Advances in Civil Engineering Materials 8(3) 327-345 [19] Gueddouda M K, Goual I, Lamara M and Mekarta B 2011 Chemical stabilization of expansive clays from Algeria Global J. of Researches in Engineering: J. General Engineering 11(5) 1-8 Reference 18 should have been referred to at the following points. [20] Kariuki PC, Shephered K D and Van Der Meer F D 2006 Spectroscopy as a tool for studying swelling soils. In: alRawas AA, Goosen, MFA editors Expansive soils-recent advances in characterization and treatment 15-24 (London, UK: Taylor and Francis Group) Table 1. The reference [18] should have been indicated in the caption Figure 2(a), Figure 2(b) and Figure 2(c). The reference [18] should have been indicated. Figure 7 the reference [18] should have been indicated. The reference (Gueddouda et al.) numbered as 18 in the older copy was corrected to 19. See the selection of the reference list above. Figure 8 should include a reference to [18]. Figure 9. The reference [18] should be indicated. The reference (Kariuki et al.) numbered 19 in the older copy was corrected in this version to 20. See attached reference list above. Table 4. The reference [18] should have been indicated References list Reference [18] was added in this version. See above list.

The field tests conducted by the American Engineering Research Associates (ERA) provided important results about the distribution and extension of the damage zones and the failure area that occurred in unlined tunnels as a result of buried explosions in the rock mass surrounding these tunnels. Despite the importance of these results, they did not include specific values for the failure thickness and the fracture angle in the damaged tunnel sections. In the current study, a 3D numerical model is used to simulate one of ERA’s tests using ABAQUS. In this model, the impact of a buried explosion on a tunnel located at (5m) away from the center of the detonation is studied. The results of this model are in good agreement with the published results of ERA’s tests. In addition, the current numerical results give complete values for the change in the failure thickness and the fracture angle over the entire length of the damaged zones of the tunnel. The results of the current study show that the thickness of the failure remains almost constant beyond damage zone 1, while the angle of the fracture decreases remarkably as the charge-to-tunnel distance increases, which causes a decrease in the failure area.