Large Scale Experiments of Buried Steel Pipelines With Elbows Subjected to Permanent Ground Deformation

Abstract

Earthquake-induced Permanent Ground Deformation (PGD) can affect significantly underground gas or water pipelines. This paper describes large-scale experiments to investigate the effect of PGD on buried steel pipelines with elbows, and to validate and calibrate Finite Element (FE) modeling. There is good agreement between both the magnitude and distribution of measured strains and deformation and those modeled with FE analyses. The analytical models are able to simulate real performance in a reliable way for dry sand, and for partially saturated sand with an adequate correction factor. Using the analytical model, recommendations are proposed for enhancing the earthquake-resistance of buried pipelines with elbows subjected to PGD.

Safety of buried steel natural gas pipelines under earthquake-induced ground shaking: A review

“…As early as 1979, Shinozuka and Koike [118] used an approximate analytical model of propagation, and concluded that these are maximized for a bend angle of about 135. There are also studies dealing experimentally [120,121] and analytically [107,122] with the static response of soilembedded pipe bends under PGD-induced in-plane bending. In a review study, Karamanos [123] describes elbows as a critical component of buried pipeline systems because they exhibit more flexible behaviour compared to straight counterparts and are more prone to section ovalization due to bending and fatigue damage under cyclic loading.…”

A critical review on the vulnerability assessment of natural gas pipelines subjected to seismic wave propagation. Part 2: Pipe analysis aspects

“…Various numerical and experimental studies have focused on the response of these elements under seismic and static loading conditions, the latter associated to seismicallyinduced permanent ground deformations, such as faulting (e.g. Shinozoka and Koike, 1979;Saberi et al, 2013;Hamada et al, 2000;Yoshizaki et al, 2003;Karamitros et al, 2016;Karamanos, 2016, among others).…”

Methods for Assessing the Seismic Resistance of Subterranean Hydro Structures Under the Influence of Seismic Waves

“…The experimental points fit well on the curve, [40,47,48], which once again confirms the insignificance of the differences in ο K for stationary and no stationary effects in a linearly elastic infinite cavity. The effect of the shape of the hole on the value was investigated [49] for square and vaulted cavities with rounded straight angles under the action of P and S waves. It turned out that in the vault the stress distribution is close to the distribution for the circular hole.…”

“…For example, in [22] it was shown that for longitudinal oscillations of a composite semi-infinite elastic rod, the spectral problem is equivalent to the problem of the natural vibrations of a finite rod with external damping of damper type. This method -the introduction of external friction -has also been used to determine the periods of natural oscillations of the chimney [7], consideration of forced oscillations of the axial symmetric viscoelastic cylindrical shell [39,49,50], the intrinsic and forced oscillations of the model of the construction-ground system [7,8], spatial forms of oscillations of the axis of symmetric structures [31]. In [29,30], the natural oscillations of a cylindrical layer in an elastic, infinite medium are investigated.…”