Numerical analysis of inclined struts and truss structure in excavation stabilization based on the damage potential index (DPI)

Document Type : Original Article

Author

Assistant Professor, Civil Engineering, Kharazmi University, Tehran, Iran

Abstract

In this research, in different conditions, the behavior of the inclined Struts support system and truss guard structure has been investigated. For this purpose, the horizontal and vertical movements of the soil due to excavation and the level of damage of buildings adjacent to these systems are determined to maintain the excavation. Excavation has been studied at three depths of 4, 7 and 10 meters, which indicate shallow, medium and high depth excavation, respectively. Mohr-Columb's behavioral criterion was used for soil behavior. The excavation was modeled in stages with PLAXIS software. Comparing the outputs obtained from numerical modeling, it was concluded that the horizontal and vertical soil displacement in the inclined Struts models is more than the truss guard structure models. The reason is the lack of vertical member and lateral bracing system in the Inclined Struts, unlike the truss guard structure. The values of stress and abutment reactions in the Inclined Struts method were obtained more than the oblique member of the truss guard structure due to the presence of more indefinite degrees in the truss, which causes stress transfer from more paths and less abutment reactions. Finally, based on the damage potential index DPI, it was determined that between the two systems of Inclined Struts and truss guard structure to stabilize the excavation in the vicinity of the neighboring building in urban areas, the safety and strength of the truss guard structure and the use of truss is safer.

Keywords

Main Subjects


  • Das,M., Sivakugan, N. (2021). Principles of Foundation Engineering.9th Edition. Cengage Learning Publisher.
  • Tavakoli, S., Aminfar, M.H., Edalati, M. (2017). Investigation the Effects of Soil Excavation on Earth Moving in Urban Areas(Case Study: Ilam City), Journal of Civil and Environmental Engineering, Vol 47, Issue 2, 21-27. (In Persian).
  • Khatami, S.R. (2007). Modeling of the method of diagonal beams in excavation with two-dimensional plaxis software, C Thesis, 2008. Ferdowsi University of Mashhad. (In Persian).
  • Fakher, A., (2005). The Mechanism of Inclined Struts in Conventional Excavation Adjacent to Existing Buildings, Report of Road, Housing & Urban Development Research Centre. (In Persian).
  • Sabzi Z, Fakher A., (2013). A Field Investigation in to the Performance of Inclined Struts connected to Adjacent Buildings During Excavation. Modares Civil Engineering journal. 2013; 13 (4) :27-43. (In Persian).
  • Skempton A.W. and MacDonald D.H. (1956). The allowable settlement of building. Structural and building division meeting, 727-768.
  • Maleki, Mahdi & Nabizadeh, Ali. (2021). Seismic performance of deep excavation restrained by guardian truss structures system using quasi-static approach. SN Applied Sciences. 3. 10.1007/s42452-021-04415-9
  • Ashraf H. (2019) Principles of excavation and Guard Structures, 2nd Ed, Iran, no avar.
  • Sabzi1 z, Fakher A. (2015) The performance of buildings adjacent to excavation supported by inclined struts. International Journal of Civil Engineering, 13: 1–15 URL: http://ijce.iust.ac.ir/article1-935-en.htm
  • Polshin D.E. and Tookar R.A. (1957) Maximum allowable non-uniform settlement of structure. 4th conf. soil Mech. Found. Eng, Vol.1, 402.
  • Burland, J.B., Broms, B.B. and De Mello, V.F.B. (1977) Behaviour of foundations and structures. 9th int. conf. soil Mech. Found. Eng2, 495-546
  • Dowding, C, H. & McKenna L.M. (2009) Crack response to long term environmental and blast vibration effects. Journal of geotechnical and geoenvironmental engineering131 pp 1151-116.
  • Boscardin M.D. & Cording E.J. (1989). Building response to excavation-induced settlement. Journal of Geotechnical and Geoenvironmental Engineering.115 No 1.
  • Boone S.J. (1996). Ground movement related building damage. Journal of Geotechnical Engineering122 No 11.
  • Son M. and Cording E.J. (2010) Estimation of building damage due to excavation-induced ground movement. Journal of Geotechnical and Geoenvironmental Engineering.131 No 2.
  • Son, and Cording, E.J. (2012) Evaluating of building stiffness for building response analyses to excavation-induced ground movement. Journal of Geotechnical and Geoenvironmental Engineering. Vol.133, No 8.
  • Juang, C.H., Shuster, M. and Ou C.Y. (2016) Fully probabilistic framework for evaluating excavation-induced damage potential of adjacent building. Journal of Geotechnical and Geoenvironmental Engineering.137, No2.
  • Halim D. & Wong K. S. (2017) Prediction of frame structure damage resulting from deep excavation. Journal of geotechnical and geoenvironmental engineering.138 No12
  • Manual PLAXIS, Finite element code for soil and rock plasticity, Delft University of Technology, Netherlands.