Numerical Study of Deep Excavations Stability with Nailing Method: Representation of Help Design Tables and Diagrams

Document Type : Research Article


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

2 Department of Civil Engineering, University of Qom, Qom, Iran


Due to the constructions rate in mega cities, deep excavations have been done in civil engineering projects in the past few years. Strengthening the excavation wall is of great importance and has been pointed out in the seventh issue of national construction rules. There are different ways of achieving the critical strength for the excavations wall, such as Truss method, reciprocal support, sheet piling, piling method, diaphragm wall, anchorage and nailing.The initial design of nailed wall in a condition that deep excavation, surcharge, and soil type are difference can be the major challenge for most designers, employers and administratives. These tables and diagrams can give good and appropriate initial view to construction industry insiders.In this article, with the change of resistance characteristic of the soil (cohesion and angle of internal friction) in the range of common soils and as well as a variety of surcharge (0 to 60 kN/m2) in the brink of the excavation, designs have been made for different deep excavation (maximum for five basements). For each excavation with different characteristics and according to valid codes, several models (on average 50 models) in the limit equilibrium (for calculation safety factor) and finite element software (for calculation displacement and force) reviewed until design have been made economic and finally provided help design tables and diagrams. Nailing system is responsive for a depth of 13 meters in the appropriate lands, but for more depth and surcharge is needed to combined system (For example combined system of nailing and anchorage).


Main Subjects

[1] H. Ashrafi, Basics of excavation and guard structures, editing National regulations office, Tehran, 2006.
[2] C. lazarte, V. Elias, d. Espinoza, p. Sabatini, Soil Nail Wall, JahadDaneshgahi, Tehran, 2011.
[3] M. Rabie, Performance of hybrid MSE/Soil Nail walls using numerical analysis and limit equilibrium approaches, HBRC, 12(1) (2014) 63-70.
[4] S. Ghareh, Parametric assessment of soil-nailing retaining structures in cohesive and cohesionless soils, Measurement, 73 (2015) 341-351.
[5] C. Lazarte, V. Elias, D. Espinoza, p. Sabatini, Soil Nail Wall, Federal Highway Administration, Washington D.C, USA, 2003.
[6] M. Puller, Deep Excavations: A Practical Manual 2nd Edition, Thomas Telford Ltd United Kingdom, 2016.
[7] S.S. Liew, c.m. khoo, Performance of Soil Nail Stabilisation Works for a 14.5m Deep Excavation at Uncontrolled Fill Ground, in: Proceedings-DFI/EFFC 10th international conference on piling and Deep Foundations, Amsterdam, Netherlands, 2006, pp. 8.
[8] G.L. Sivakumar Babu, S. Vikas Pratap, Numerical analysis of performance of soil nail walls in seismic conditions, ISET Journal of Earthquake Technology, (2008).
[9] C.W.W. Negi, R.Z.B. ZHOU, M. ZHANG, The effects of soil nails in serviceability of soil nailed slopes, University of Dundee, uk, 2006.
[10] J.L. Briaud, Y. Lim, Tieback Walls In Sand: Numerica Simulation And Desing Implications, Rep., College Station, Texas, 1996.