Deep Excavation Analysis Supported by Anchored Diaphragm Walls: A comparison of Constitutive Models

Authors

  • Hind K. Nasir Department of Civil Engineering /College of Engineering/University of Duhok/1006 AJ Duhok, KR-Iraq.
  • Rafi’ M. Sulaiman Al-Ne’aimi Department of Civil Engineering /College of Engineering/University of Duhok/1006 AJ Duhok, KR-Iraq.

DOI:

https://doi.org/10.25007/ajnu.v13n1a1646

Abstract

This paper presents a numerical study of a large and deep excavation in clay soil supported by anchored diaphragm walls under unequal load to investigate the influence of several design parameters on the stability and safety of the supporting system and their impacts on the surrounding nearby structures using the Plaxis 2D v20 code. The numerical model result was compared with a case study of braced excavation in the clays, and a close match between the results was observed. The soil profile consists of several clay layers and is modeled with two constitutive modes: the Mohr-Coulomb model (MCM) and the hardening soil with a small strain model (HSsmall). The diaphragm walls were modeled as plates and the anchor rods as node-to-node connections. The studied parameters include the inclination angle of anchors, number of ground anchors, surface load magnitude, various ratios of wall-embedded depth to the excavation depth on a deep excavation, and the heave developed at the bottom of the excavation. It was observed that as  is increased from 0.3 to 0.5,  and  is reduced by approximately 6.7% and 14.7%, respectively, for the MCM, compared to 10.5% and 8.1% by the HSsmall modeling. Whereas  increased to 0.7, the values of  and  in both models remained unchanged. Furthermore, for all studied ratios, the MCM produces around 28 mm of heave compared to 23 mm for the HSsmall model. In general, the outcome results of the analysis were examined and discussed in terms of maximum values of lateral displacements, bending moments in the wall supporting system, and the settlement of the ground surface behind both sides of the excavation, which can serve as a reference for deep excavation design and similar geotechnical problems.

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References

Abdel-Fattah, E.-S., A. A. E. Hegazy and E. M. A. G. Awaad (2018) "Analysis of the behavior of inclined anchor by varying the inclination and elevation of a tie."

Bathe, K.-J. (1996). "Finite Element Procedures Prentice-Hall." New Jersey 1037: 1.

Brinkgreve, R., L. Zampich and N. Ragi Manoj (2019). "PLAXIS Scientific Manual CONNECT Edition V20." Delft, Netherlands.

Capraru, C. and A. Chirica (2012). "Numerical modeling and constitutive soil models for deep excavations analysis." International Multidisciplinary Scientific GeoConference: SGEM 2: 215.

Chowdhury, S. S., K. Deb and A. Sengupta (2013). "Estimation of design parameters for braced excavation: a numerical study." International Journal of Geomechanics 13(3): 234-247.

El-Nahhas, F. and M. Morsy (2002). Comparison of the measured and computed performance of propped diaphragm retaining wall in Egypt. Proc. of the Int. Symposium on Numerical Models in Geomechanics, Rome, Italy.

Engin, A. (2019). Finite element analysis of a deep excavation: a case study, Middle East Technical University.

Fayed, A. (2002). Numerical modeling of underground subway stations, Ph. D. Thesis, Geotechnical and Foundation Engineering, Ain Shams University ….

Johansson, E. and E. Sandeman (2014). Modelling of a deep excavation in soft clay a comparison of different calculation methods to in-situ measurements.

Korff, M., R. Mair, A. Van Tol and F. Kaalberg (2012). "The response of piled buildings to deep excavations." Geotechnical aspects of underground construction in soft ground. London: Taylor & Francis.

Li, L.-x., J.-d. Liu, K.-j. Li, H. Huang and X. Ji (2019). "Study of parameters selection and applicability of HSS model in a typical stratum of Jinan." Rock Soil Mech 40 (10): 4021-4029.

Likitlersuang, S., C. Surarak, D. Wanatowski, E. Oh and A. Balasubramaniam (2013). "Finite element analysis of a deep excavation: A case study from the Bangkok MRT." Soils and Foundations 53(5): 756-773.

Mei, Y., D. Zhou, X. Wang, L. Zhao, J. Shen, S. Zhang and Y. Liu (2021). "Deformation law of the diaphragm wall during deep foundation pit construction on the lake and sea soft soil in the Yangtze River Delta." Advances in Civil Engineering 2021.

Mitew-Czajewska, M. (2017). FEM modeling of deep excavation–parametric study, HypoplasticClay model verification. MATEC Web of Conferences, EDP Sciences.

Mitew-Czajewska, M. (2018). "Parametric study of deep excavation in clays." Bulletin of the Polish Academy of Sciences. Technical Sciences 66 (5).

Obrzud, R. F. (2010). "On the use of the Hardening Soil Small Strain model in geotechnical practice." Numerics in geotechnics and structures 16: 1-17.

Schweiger, H. (2009). Influence of constitutive model and EC7 design approach in FEM analysis of deep excavations. ISSMGE Int. Seminar on Deep Excavations and Retaining Structures, ISSMGE Hungarian National Committee.

Schweiger, H. and H. Breymann (2006). FE-analysis of five deep excavations in lacustrine clay and comparison with in-situ measurements. Geotechnical aspects of underground construction in soft ground. Proceedings of the 5th international conference of TC 28 of the ISSMGE, the Netherlands, 15-17 June 2005.

Schweiger, H. F. (2007). "Modelling issues for numerical analysis of deep excavations." Institute for Soil Mechanics and Foundation Engineering Graz University of Technology, Austria.

Tjie-Liong, G. (2014). "Common mistakes on the application of Plaxis 2D in analyzing excavation problems." International Journal of Applied Engineering Research 9 (21): 8291-8311.

Zain, M. N., J. Ahmad, Y. Ashaari, E. Shaffie and N. Mustaffa (2011). Modeling of Lateral Movement in Soft Soil Using Hardening Soil Model. 2011 UkSim 13th International Conference on Computer Modelling and Simulation, IEEE.

Kulkarni S. R. ‘Analysis of deep excavation using PLAXIS 2D’. M tech Thesis, Department of Civil Eng, COEP (2014).

Published

2024-03-31

How to Cite

K. Nasir , H. ., & M. Sulaiman Al-Ne’aimi , R. . (2024). Deep Excavation Analysis Supported by Anchored Diaphragm Walls: A comparison of Constitutive Models. Academic Journal of Nawroz University, 13(1), 186–204. https://doi.org/10.25007/ajnu.v13n1a1646

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Articles