ABSTRACT
The BiP-k θ and BiP-η models and solutions well capture response of piles subjected to excavation loading (i.e., a mixed translation-rotational soil movement). Each model represents a flexible pile as bi-portions (BiP, namely upper and lower portions), which join together by a rotational spring at the depth of maximum bending moment (z m). The upper (rigid) portion rotates about the depth z m at a constant rotational stiffness of k θ (BiP-k θ model), which is capped by elastic restraint from lower portion (R-E model). The bi-portions may have a constant rotation ratio η (BiP-η model), which is rigorously related to the stiffness (k θ ). The models reveal and quantify response amplification for inward-rotating bi-portions. They were adopted to gain response of piles in centrifuge tests subjected to excavation loading, and impact of the five input parameters [i.e., limiting force per unit length (FPUL), modulus of subgrade reaction, modulus ratio of stable over sliding layers, and rotational stiffness of each portion] on the predictions.
