Investigating the soil consolidation via vacuum method by using numerical analysis

Document Type : Research Article


1 Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran

2 Department of civil engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran

3 Department of Civil Engineering, Engineering Faculty, Islamic Azad University, Central Tehran Branch


Due to increasing population and urbanization and lack of suitable land in terms of bearing capacity, construction is performed on soft soils, especially clays with low bearing capacity and excessive conventional settling characteristics. In these types of saturated soils, the construction of structures, such as large buildings, will release pore water pressure and therefore create a consolidation. One of the ways to reduce consolidation to the permissible amount specified in the regulations is to use a preload method that will require soil and embarkment operations and ultimately, necessity the removal of those embarkments. Vacuum combined with vertical drainage is an effective way to reduce the number of soil operations and associated costs, which in other words will accelerate the construction of structures and reduce costs. In this study, the effect of several parameters on the amount of consolidation was investigated by simulating soil consolidation via using the COMSOL Multiphysics and GeoStudio software. Based on the results, it was found that increasing vacuum intensity in vacuum chambers, increasing soil void ratio, and increasing bedrock depth, each of them accelerated the consolidation process. However, the number of vacuum terminals does not have a significant impact on this process.


Main Subjects

[1] Masse, F., et al., Vacuum Consolidation -A Review of 12 Years of Successful Development, (2001)
[2] Schiffman, R.L. Consolidation of soil under time-dependant loading and varying permeability, in: Highw. Res. Board Proc., 1958.
[3] Wilson, N.E., Elgohary, M.M. Consolidation of soils under cyclic loading, Can. Geotech. J. 11 (1974) 420–423.
[4] Alonso, E.E., Krizek, R.J. Randomness of settlement rate under stochastic load, ASCE J Eng Mech Div. 100 (1974) 1211–1226.
[5] Olson, R.E. Consolidation under time-dependent loading, J. Geotech. Eng. Div. 103 (1977) 55–60.
[6] Baligh, M.M., Levadoux, J.N. Consolidation theory for cyclic loading, J. Geotech. Eng. Div. 104 (1978) 415–431.
[7] Ying-chun, Z., Kang-he, X., Xi-bin, L. Nonlinear analysis of consolidation with variable compressibility and permeability, J. Zhejiang Univ. A. 6 (2005) 181–187.
[8] Chai, J.-C., Carter, J.P. and Hayahsi, S. Ground deformation induced by vacuum consolidation. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 131(12), (2005) 1552–1561.
[9] Chai, J.-C., Miura, N. and Bergado, D. T. Preloading clayey deposit by vacuum pressure with cap-drain: Analyses versus performance. Geotextiles and Geomembranes, 26(3), (2008) 220–230.
[10] Toufigh, M.M., Ouria, A. Consolidation of inelastic clays under rectangular cyclic loading, Soil Dyn. Earthq. Eng. 29 (2009) 356– 363.
[11] Chai, J.-C., Hong, Z.-S. and Shen, S.-L. Vacuum-drain consolidation induced pressure distribution and ground deformation. Geotextiles and Geomembranes, 28(6), (2010) 525–535.
[12] Kosaka T, KawaidaM, Yamada K and ToyotaM., 10 meters of ground settlement behaviors induced by vacuum consolidation and high embankment highway construction. Proceedings of the 46th Annual Meeting of Japanese Geotechnical Society, Kobe, Japan, (2010) 853–854 (in Japanese).
[13] Chai JC, Ong CY, Carter JP and Bergado DT., Lateral displacement under combined vacuum pressure and embankment loading.Ge´otechnique 63(10), (2010) 842–856
[14] Indraratna, B., Recent advances in the application of vertical drains and vacuum preloading in soft soil stabilisation, (2010).
[15] Kargar, S., Moosavi, A. Bidirectional water transport through non-straight carbon nanotubes, J. Mol. Liq. 276 (2019) 39–46.
[16] Rujikiatkamjorn, C., Indraratna, B., Chu, J. 2D and 3D numerical modeling of combined surcharge and vacuum preloading with vertical drains, Int. J. Geomech. 8 (2008) 144–156.
[17] Reihani, A., Soleimani, A., Kargar, S., Sundararaghavan, V., Ramazani, A. Graphyne Nanotubes: Materials with Ultralow Phonon Mean Free Path and Strong Optical Phonon Scattering for Thermoelectric Applications, J. Phys. Chem. C. 122 (2018) 22688–22698.
[18] Dam, L.T.K, Sandanbata, I and Kimura, M., Vacuum Consolidation Method-Worldwide Practice and the Latest Improvement in Japan (2006)
[19] Walker, R., Indraratna, B. Consolidation analysis of a stratified soil with vertical and horizontal drainage using the spectral method, (2009).  
[20] Mohamedelhassan, E., Shang, JQ., Vacuum and surcharge combined one-dimensional consolidation of clay soils, Canadian Geotechnical Journal 39 (5), (2002) 1126-1138
[21] Indratna, B., Rujikiatkamjorn, C., Ameratunga, J. and Boyle, P., Performance and Prediction of Vacuum Combined Surcharge Consolidation at Port of Brisbane. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 137(5), (2011) 550–554.
[22] "COMSOL Modeling Software". Comsol, Inc. Retrieved 20 November 2015.
[23] GEO-SLOPE International Ltd, GeoStudio 2007 Add-Ins Programming Guide and Reference[M]. 2007.