Mohamed Abdel-Rahman and Ashraf Ghaly
Association of Egyptian-American Scholars
Anchors are structural elements used in geotechnical and foundation works to provide stability to structures subjected to pullout or uplift forces. Their applications range widely from supporting transmission power lines to providing resistance to sheet pile walls. Anchors may be used as vertical supporting elements or may be installed at an angle and they are designed to resist forces acting along their axis Depending on the function it serves, the anchor design is usually impacted by the following parameters: diameter, depth of installation, angle of installation, type of field soil, presence of water, and method of installation. The ultimate pullout capacity of anchors is determined as the maximum load that an anchor can resist provided that displacement recorded at that load did not exceed the acceptable serviceability limit. The ultimate pullout capacity of anchors may also be defined as the load an anchor resists at the maximum allowed displacement. This study presents the results of limit state Analysis using the software LimitState:GEO to examine the pullout capacity of anchors installed in dry sand. The software LimitState:GEO is a general purpose software which is designed to rapidly analyze the ultimate limit state (or ‘collapse state’) for a wide variety of geotechnical problems and it is designed for use with Eurocode 7. The software can be used to model 2D problems of any geometry specified by the user including slopes, retaining walls, foundations, sheet piles, pipelines, tunnels, anchors etc. and any combination of these. it directly determines the ultimate limit state (ULS) using the computational limit analysis technique to identify the failure mechanisms using the efficient numerical analysis procedure ‘Discontinuity Layout Optimization’ (DLO) to provide an automatic means of identifying accurate limit analysis solutions. The DLO analysis procedure establishes the critical failure mechanism and analyses the ultimate limit state by factoring loads or material strengths. The present investigation conditions are similar to those used in an experimental program carried out in the laboratory. The goal was to improvise the limit state analysis to closely predict results similar to those obtained in the laboratory in order to extend the results to full scale anchors similar to those used in the field. This should help in closely predicting the performance of field anchors, thus elevating the level of confidence in the design process.
This article was published in 3alamaltanmya
sponsored by Future Builders International Academy
Led by Dr.Maha Fouad