Modelling of upheaval buckling of offshore pipeline buried in clay soil using genetic programming

A new finite element model of buried steel pipelines crossing strike-slip faults considering equivalent boundary springs

“…Combining the unanchored length of L obtained above, the length of the referred model was increased to 2500 m to fully reflect the interaction of the pipeline-soil, which coincided with the dimension of the models proposed in the works of Joshi et al [17] and Vazouras et al [16,18]. In the range of [À30 m, 30 m], the referred model was identical to the proposed model, while in the ranges of [À30 m, À1250 m] and [30 m, 1250 m], the pipeline was modeled as 3-D beam elements, and the soil was modeled as spring elements [26,27], whose properties were calculated based on ALA-ASCE guidelines [23] (see Table 2). …”

Offshore pipeline performance evaluation by different artificial neural networks approaches

“…The problem of this paper is same as that presented in the authors' previous paper [12]. In that paper, we modelled the upheaval buckling values by genetic programming (GP).…”

“…Respective mean values and corresponding coefficient of variation (CoV) of the parameters together with assigned probability distribution are same as those reported in the previous papers [14,12]. The response of pipeline is affected by the uncertainties associated in soil and pipe properties and operational conditions.…”

“…The pipe was modelled with elastic beam element while the seabed and cover soils were modelled with elastic zero-length spring element. Properties of the materials used and the schematic diagram of the buried pipeline have been given in the previous paper [12].…”

“…Although the results obtained by GP were accurate, the results of this paper will show that ANNs model is a better tool to evaluate the problem of this paper. As it has been provided in the previous paper [12], the steel offshore pipeline of 500 m is considered for the analysis by a 2D finite element model in OpenSEES software. The pipe was modelled with elastic beam element while the seabed and cover soils were modelled with elastic zero-length spring element.…”