Determining the inclination angles of anchor bolts for sliding and toppling failures: a case study of İzmir, Türkiye

Koca M. Y., Kıncal C., Onur A. H., Kadakci Koca T.

BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT, cilt.82, ss.1-20, 2023 (SCI-Expanded)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 82
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1007/s10064-022-03063-6
  • Dergi Adı: BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, IBZ Online, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Compendex, Environment Index, Geobase, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.1-20
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

When anchors are installed along or close to discontinuity surfaces in a jointed rock slope, it is very difficult for them to bond

to the rock mass. The correct orientation of rock anchors should be selected for precise design. Hence, using stereographic

projection to reveal the geometrical relationships among the slope face, discontinuities, and anchor bolts is vital. In support

measures, the inclination of the anchor bolt is affected by many factors, such as the feasibility and difficulty of construction.

Therefore, it should be based on the analysis results of stereographic projection. This study aims to determine the most

suitable anchor inclination angle based on geometrical information using stereographic projection techniques to provide the

stability to excavation slopes. Remarkable stereographic projection images such as “an opened umbrella” and “an upsidedown

umbrella” for planar and toppling failures, respectively, were obtained. The most suitable anchor inclination angles for

both planar and toppling failures were determined by investigating the largest acute angle between the discontinuity plane

and the anchor bolt on the stereographic projection. Additionally, a computer program based on basic geometric relations

was developed to determine the most suitable inclination angle for rock anchors installed perpendicular to the slope face.

Using both stereographic projection techniques and computer software, the most suitable anchor inclination angles for planar

slides and toppling failures were determined to be 17° and 11°, respectively. However, this method may not be reliable in

determining the suitable inclination angle of rock anchors in highly fractured rock masses.