Performance of Steel Pipeline with Concrete Coating (Modeled with Concrete Damage Plasticity) Underseismic Wave Passage

Joanna M. Dulinska,Dorota Jasinska

doi:10.4028/www.scientific.net/amm.459.608

Joanna M. Dulinska, Dorota Jasinska

Open Access

https://doi.org/10.4028/www.scientific.net/amm.459.608

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Abstract

The paper presents the analysis of the dynamic response of a steel pipeline with concrete coating to a real earthquakeregistered in central Poland in 2012. The peak ground acceleration of the shock was scaled up to maximal values predicted for this seismic zone. To represent theinelastic behavior of the material of the concrete coating under dynamic loading, the concrete damaged plasticity constitutive model was assumed.The modelallows to describeplastic strains and irreversible tensile and compression damage that occurs during the cracking process.For seismic analysis two models (uniform and non-uniform) of kinematic excitation were applied. In the modelof uniform excitation it was assumed that the motion of all supports was identical. Inthe model of non-uniform excitation, typical for long structures, the wave passage along the pipelinewith different velocities (500, 400 and 300 m/s) was taken into account. It occurred that for the model of uniform excitation the concrete material of the coating remained elastic with no tensile damage. For the model of non-uniform excitation, inelastic behaviour of the coating was observed. The plastic strain areas appeared above all supports. The tensile damage (cracking) wasalso noticed in these areas: the lower wave velocity was assumed, the greater area of concrete coating was affected by plastic strains and tensile damage (cracking). It was the consequence of the quasi-static effects which resulted from ground deformations imposed on the pipeline during the seismic shock.

Highlights

During earthquakes long structures are exposed to spatially different ground vibrations, since their dimensions are comparable with the wave length propagating in the ground
To represent the inelastic behavior of the concrete coating of the steel pipeline a continuum, plasticity-based, damage model called concrete damaged plasticity (CDP) was assumed as a constitutive model for the concrete [5, 6].The model, provided by the ABAQUS software, is designed for applications in which concrete is subjected to cyclic, dynamic loading like during an earthquake.The model combines non-associated multi-hardening plasticity and scalar damaged elasticity to describe the irreversible damage that occurs during the fracturing process
- For the model of uniform seismic excitation the concrete material of the coating remained elastic with no tensile damage, - For the model of non-uniform seismic excitation, which takes theso called wave passage effect into account, inelastic behaviour of the concrete coating could be observed

Summary

Introduction

During earthquakes long structures are exposed to spatially different ground vibrations, since their dimensions are comparable with the wave length propagating in the ground. Rough terrain configurations such as steep slopes, and for road and river crossings, steel pipelines are covered with concrete coatings. Such coatingsoffer excellent protection of steel pipesfrom both mechanical impact and chemical corrosion. Different velocities of wave propagation are taken into account.The analysis of the pipeline dynamic response to a small earthquakeis carried out for a 100 m long section of a steel pipeline with concrete coating.The material of the coating is described with a concrete damage plasticity model [5, 6]

The main data of the investigated pipeline

Constitutive parameters for concrete damaged plasticity model

Seismic input data

Conclusions