The Investigation of Traffic and Near-Field Earthquake Loads Effects on the Nailed and Braced Excavations

Document Type : Research Article

Authors

1 Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

2 Department of Civil Engineering, ACECR, Academic Center for Education, Culture and Research, Khouzestan Branch, Ahvaz, Iran

Abstract

Considering the statistical and probabilistic characteristics of construction conditions, the investigation of dynamic overloads' effects on the urban excavation wall is of great importance. In the present study, the performance of nailed and braced excavations under two vibrational dynamic excitations, traffic and near-field earthquake loads, have been investigated in four regions of Ahvaz. Critical boreholes with the lowest static bearing capacity have been selected by analyzing the layers' strength parameters in each region. Numerical models have been designed to limit the seismic waves' reflection at the excavation boundaries with 20 x 100 meters and with absorbing walls. Also, the damping ratio was assumed to be 2%. A harmonic wave at different speeds has simulated the excitation caused by the traffic passage. Resonant frequencies due to traffic-induced vibration have been recorded in the speed range of 56 to 72 km/hr. Due to the traffic load, the bracing and the nailing systems showed fewer vertical and lateral displacements, respectively. Moreover, the excavations have been analyzed under 7 acceleration with compatible near field characteristics of the Ahwaz plan acceleration (0.25g). The Golestan region showed the highest displacement difference between the two systems. Due to earthquake loads, the nailed system showed less vertical displacement and the braced system showed less horizontal displacement. The error of the analytical models' results in vertical displacement was 15% and in lateral displacement was 26% less than a nailed excavation located in the Kiyanpars region.

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References

[1] L. Sun, T.W. Kennedy, Spectral analysis and parametric study of stochastic pavement loads, Journal of engineering mechanics, 128(3) (2002) 318-327.
[2] D. Chavan, G. Mondal, A. Prashant, Seismic analysis of nailed soil slope considering interface effects, Soil Dynamics and Earthquake Engineering, 100 (2017) 480-491.
[3] C.-C. Fan, J.-H. Luo, Numerical study on the optimum layout of soil–nailed slopes, Computers and Geotechnics, 35(4) (2008) 585-599.
[4] G. Kouroussis, L. Van Parys, C. Conti, O. Verlinden, Using three-dimensional finite element analysis in time domain to model railway-induced ground vibrations, Advances in Engineering Software, 70 (2014) 63-76.
[5] L.M. Gil-Martín, E. Hernández-Montes, M. Shin, M. Aschheim, Developments in excavation bracing systems, Tunnelling and underground space technology, 31 (2012) 107-116.
[6] A. Alipour, A. Eslami, Design adaptations in a large and deep urban excavation: Case study, Journal of Rock Mechanics and Geotechnical Engineering, 11(2) (2019) 389-399.
[7] H. Xia, Y. Cao, G. De Roeck, Theoretical modeling and characteristic analysis of moving-train induced ground vibrations, Journal of Sound and Vibration, 329(7) (2010) 819-832.
[8] M. Mhanna, M. Sadek, I. Shahrour, Numerical modeling of traffic-induced ground vibration, Computers and Geotechnics, 39 (2012) 116-123.
[9] L. Sun, W. Gu, F. Luo, Steady state response of multilayered viscoelastic media under a moving dynamic distributed load, J. Appl. Mech. ASME, 75(4) (2009) 1-15.
[10] L. Sun, Y. Duan, Dynamic response of top-down cracked asphalt concrete pavement under a half-sinusoidal impact load, Acta Mechanica, 224(8) (2013) 1865-1877.
[11] J.P. Stewart, S.-J. Chiou, J.D. Bray, R.W. Graves, P.G. Somerville, N.A. Abrahamson, Ground motion evaluation procedures for performance-based design, Soil dynamics and earthquake engineering, 22(9-12) (2002) 765-772.
[12] J.B. Burland, B.B. Broms, V.F. De Mello, Behaviour of foundations and structures,  (1978).
[13] J. Burland, Assessment of risk of damage to buildings due to tunnelling and excavation, 1997.
[14] A. Fakher, S. Yasrobi, I. Naeimifar, Allowable limit of soil nail wall deflection based on damage level of adjacent structures(in persian), tarbiat Modares University Journals, 16(2) (2016) 257-271.
[15] T. Schanz, P. Vermeer, P. Bonnier, The hardening soil model: formulation and verification, Beyond 2000 in computational geotechnics,  (1999) 281-296.
[16] G. Miller, H. Pursey, E.C. Bullard, On the partition of energy between elastic waves in a semi-infinite solid, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 233(1192) (1955) 55-69.
[17] a. ghanbari, m. eftekhar manesh, t. tajik, the analysis of stabilized deep excavations in nailing and anchor combonation method under harmonic dynamic loads in FEM-case study (in persian),  (2015).
[18] B.-C.B. Hsiung, K.-H. Yang, W. Aila, C. Hung, Three-dimensional effects of a deep excavation on wall deflections in loose to medium dense sands, Computers and Geotechnics, 80 (2016) 138-151.
[19] Y. Xu, X. Hong, Stochastic modelling of traffic-induced building vibration, Journal of sound and vibration, 313(1-2) (2008) 149-170.
Amirkabir Journal of Civil Engineering
Volume 54, Issue 2
May 2022
Pages 495-520

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