It is verified that, under certain continuity conditions, the boundary inte
gral equations (BIEs) of both displacement and displacement derivative can
be expressed in a variety of regularized forms with at most weak singularit
ies for any points within the domain or on its boundary. A series of algori
thms embedded in the regularized formulations are presented to calculate th
e field variables within the domain or on its boundary. Detailed numerical
results are given to check and compare the validities of the proposed algor
ithms and some practical effective algorithms are discovered. Due to the ch
aracter of the at most weak singularities in the formulations, the algorith
ms require no special numerical treatments, but only the general Gauss quad
rature to implement. To the end, the continuity requirements for the field
variables and the validities of the algorithms are discussed. (C) 2001 Else
vier Science Ltd. All rights reserved.