An innovative approach to the design of ground anchors

conference paper

English

Determination of the ground anchors ultimate carrying capacity is mostly conducted using various empirical and semi-empirical methods. These procedures are usually successful but highly simplified. Wide range of empirical factors is required, which knowledge is limited only for certain types of soils. One of the major simplifications of these methods is an assumption that the bond stress on the soil – grout interface is mobilized uniformly along the whole fixed length. The result of these methods is mostly only ultimate carrying capacity with no additional information about the displacement required to mobilize this ultimate force. An innovative approach incorporating load transfer functions [2] is therefore proposed. A load transfer function (t-z curve) is the dependence of shear stress mobilized on the surface of a member on the vertical displacement of a corresponding member. The load transfer function is frequently adopted for determination of the load – settlement curve of vertically loaded piles; however its use for ground anchors is rare. The important feature of the proposed approach is the possibility to determine t-z curves as a combination of standard laboratory tests results (e. g. direct shear test) and certain assumption of shear stress mobilization in radial direction [4]. Employing load transfer functions with shear strength envelope determined from series of direct shear tests is demonstrated on the back analysis of prestressing tests carried out on ground anchors fabricated on the construction site "Optimization of the railway section Krasíkov – Česká Třebová".

ground anchors, carrying capacity, load – transfer function, shear stress, prestressing tests

CHALMOVSKÝ, J.; ŠTEFAŇÁK, J.; MIČA, L.

2015

18. 6. 2015

978-619-7105-32-2

SGEM2015 Conference Proceedings

1314-2704

International multidisciplinary geoconference SGEM

2

Republic of Bulgaria

25

32

7