![Na-tech seismic risk
Dynamic geotechnical effects
The seismic performance of the pipeline
depends on the form of deformation of the
soil, it can be transient or permanent.
Deformation types Seismic parameters
Strong Ground Shaking
(SGS)
Peak Ground Velocity
(PGV)
Ground Failure
(GF)
Peak Ground Acceleration
(PGA)
Seismic fragility
Probability to have damage if the
earthquake demand D in terms of IM is
greater than the capacity of the element.
It's a cumulative distribution function.
Fragility = f [D ⩾ C| IM]
Empirical
correlations
Repair
Rate
RR = a × IMb [n° repairs/km]
Fragility
(HAZUS)
𝑃 𝑁 = 𝑛 = 𝑒!""∗$
∗
(""∗$)!
'!
Pf= 1 − 𝑃 𝑁 = 0 =
1 − 𝑒!""∗$
a and b are parameters defined on the basis of a regressive analysis of the damage
data on the available underground pipelines.](https://image.slidesharecdn.com/seismicvulnerabilityofhydrogenpipelines-210812144732/85/Seismic-vulnerability-of-hydrogen-pipelines-6-320.jpg)
Seismic vulnerability of hydrogen pipelines
- 1. SEISMIC VULNERABILITY OF HYDROGEN PIPELINES Case study for three European regions by Cornelio Agostinho
- 2. Introduction The Hydrogen transport by pipelines is more reliable and efficient than transport in pressure tanks. As we can see from the graph hydrogen has low energy per volume unit, instead of the energy per mass unit which, has highs values, which means that if we choose the batch method, we transport less energy. V!!,#$ ≈ 38 𝑙𝑡 per 1 kg!! @ 300 𝑏𝑎𝑟
- 3. Introduction Pure H2 Transport: Newly Built Pipeline Materials Criticality Steel(C<0,2) Hydrogen Embrittlement HDPE P Operating Transport of H2 mixed with Natural Gas Existing Natural Gas Pipeline Concentration Limits by weight of H2 in the gas mixture
- 4. Work’s Objectives Construction of fragility curves and estimation of the probability of damage caused by earthquakes in hydrogen pipelines. Component under analysis Material Seismic data Place Hydrogen Pipeline Steel and HDPE Hazard curves in PGA and PGV Bavaria, Sicily and Maastricht Combined analysis betwen Seismic Geology Industrial Engineering PSHA data collection and subsequent application to Na-tech Risk in the specific case of hydrogen pipelines. Approach:
- 5. Design and construction Models Input Example Mathematical Models of Optimization Production Sites Storage Sites Transport Economic aspects MILP/MINLP Space GIS Based on transition scenarios GAMS Methods for Network Design TECHNIQUES FOR THE INSTALLATION OF HYDROGEN PIPELINES BURIED ON THE SURFACE -Used in rural or uninhabited areas -Requires the use of pipe supports -Requirements for the surface of the soil hollow opening NO-DIG methods
- 6. Na-tech seismic risk Dynamic geotechnical effects The seismic performance of the pipeline depends on the form of deformation of the soil, it can be transient or permanent. Deformation types Seismic parameters Strong Ground Shaking (SGS) Peak Ground Velocity (PGV) Ground Failure (GF) Peak Ground Acceleration (PGA) Seismic fragility Probability to have damage if the earthquake demand D in terms of IM is greater than the capacity of the element. It's a cumulative distribution function. Fragility = f [D ⩾ C| IM] Empirical correlations Repair Rate RR = a × IMb [n° repairs/km] Fragility (HAZUS) 𝑃 𝑁 = 𝑛 = 𝑒!""∗$ ∗ (""∗$)! '! Pf= 1 − 𝑃 𝑁 = 0 = 1 − 𝑒!""∗$ a and b are parameters defined on the basis of a regressive analysis of the damage data on the available underground pipelines.
- 7. State Hazard Consequence (Structural Damage) DS0 Low Negligible damage; pipe bending DS1 Significa nt Longitudinal and circumferential ruptures; joints compression. DS2 High Breaks for CPs; Loss of joints in pipelines. Stato Hazard Patterns (loss of containment) RS0 Null No loss RS1 Low Very limited losses: Toxic (D < 1 mm/m) -Inflammable (D < 10 mm/m) RS2 High Not negligible losses Risk Status (RS): Seismic vulnerability models of hydrogen pipelines Damage Status (DS) It is related to the release of dangerous content. Pipelines Material Joints Mode of damage Continuo (CP) Steel(C<0,2) Polyethylene (HDPE) Welded; Mechanical; Special. Tension cracks; Compression cracks Local buckling; Beam buckling. Segmented (SP) PVC, Vitrified, Sand, Cast Iron Mechanical, Welded Torsion or breaking Structural Aspects of H2 Pipelines
- 8. Seismic parameter and Probability of damage Types of Installation of the Pipeline IM to use Motivation Buried Peak Ground Velocity(PGV) Related to the longitudinal tension of the soil. Above ground Peak Ground Acceleration(PGA) Related to the inertial response of the pipe. Probability of damage Is the cumulative Probability of damage or loss of the content given by the combination of the function of vulnerability (fragility) and the danger function seismic h(IM) in a specific pipeline. 𝑃 𝑅𝑆 ≥ 𝑅𝑆! 𝐼𝑀 = ∫ "# 𝑃 𝑅𝑆 ≥ 𝑅𝑆! 𝐼𝑀 . ℎ(𝐼𝑀)𝑑𝐼𝑀 The Fragility Curves express the fragility of each component compared to the seismic intensity parameter Fragility 𝑃 𝐷𝑆 ≥ 𝐷𝑆! 𝑜𝑟 𝑅𝑆 ≥ 𝑅𝑆! = 1 2 1 + 𝑒𝑟𝑓 ln 𝐼𝑀 − ln 𝜇 𝛽 2
- 9. The Repair Rate is an indicator of pipeline performance that derives from a fetting of post-earthquake data present in the literature. Fragility curve in RR Relation Reference Validity RR=K1(0,00187).PGV ALA(2001) K1=0,6 Acciaio K1=0,5 HDPE RR=(PGV/50)2,67 O’Rourke and Ayala (1993) HDPE e Ghisa RR=2,88x10-6 x(PGA- 100)1,97 Isoyama et al. (2000) Tubature fatte in Ghisa Empirical Relationships of Fragility Hazard curves and calculation procedure 1,00E-05 1,00E-04 1,00E-03 1,00E-02 1,00E-01 1,00E+00 0,00E+00 2,00E+01 4,00E+01 6,00E+01 8,00E+01 1,00E+02 1,20E+02 RR/km di distanza PGV(cm/s) Repair rate HDPE buried Steel buried
- 10. Hazard curves and calculation procedure 0,00E+00 5,00E-02 1,00E-01 1,50E-01 2,00E-01 2,50E-01 3,00E-01 0,0E+002,0E+014,0E+016,0E+018,0E+011,0E+02 Probabilità PGV(cm/s) Hazard curves express the probability or frequency of Excess (EP) of a given seismic intensity value in a period of time Y. 2- Fragility curve 1-Hazard curve The probability of damage is given by the combination of the function of fragility with the Seismic Hazard Function h(IM) 3-Probability of damage Lanzano et al. (2013) Seismic Risk Analysis is a combination of three factors which are: seismic risk, exposure to seismic risk and fragility. Structural aspects Class Fragility Risk state, RS μ (cm/s) β CP ≥ RS1 37,21 0.29 CP = RS2 63,25 0,12
- 11. Case study 1: Bavaria (Germany) 0,00E+00 5,00E-02 1,00E-01 1,50E-01 2,00E-01 2,50E-01 3,00E-01 0,0E+00 2,0E+01 4,0E+01 6,0E+01 8,0E+01 1,0E+02 Probabilità PGV(cm/s) Prob. of damage PP buried RS=RS2 4,00E-02 4,00E-01 1,00E-02 1,00E-01 1,00E+00 1,00E+01 1,00E+02 Probability of exceedance(1/y) PGV(cm/s) HAZARD CURVE 0,00E+00 2,00E-06 4,00E-06 6,00E-06 8,00E-06 1,00E-05 1,20E-05 1,40E-05 1,60E-05 6,00E+00 2,60E+01 4,60E+01 6,60E+01 8,60E+01 1,06E+02 Probabilità PGV(cm/s) Prob. of damage PP buried RS>=RS1 Probability of damage
- 12. Probability of damage Case study 1: Bavaria (Germany) 1,00E-06 1,00E-05 1,00E-04 1,00E-03 1,00E-02 1,00E-01 1,00E+00 0,0009 0,001 0,002 0,003 0,004 0,005 0,007 0,0098 0,0137 0,0192 0,0269 0,0376 0,0527 0,0738 0,103 0,145 0,203 0,284 0,397 0,556 0,778 Exceedance Probability 1 y PGA(cm/s^2) Hazard curve 0,00E+00 2,00E-05 4,00E-05 6,00E-05 8,00E-05 1,00E-04 1,20E-04 1,40E-04 0 0,5 1 1,5 2 2,5 Probabilità PGA(m/s^2) Probability of Damage Above Ground Steel Pipeline(WS, SGS, CP) RS>=RS1 RS=RS2
- 13. Case study 2: Maastricht (Netherlands) 0,0001 0,001 0,01 0,1 1 0,001 0,01 0,1 1 10 Exceedance Probability (1y) g Hazard Curve 0,0001 0,0006 0,0011 0,0016 0,0021 0,0026 0,0031 0,0036 0,0041 0 1 2 3 4 Probabilità PGA(m/s^2) Probability of Damage Above Ground Steel Pipeline(WS, GF, CP) RS>=RS1 RS=RS2 Maximum probability for a g of 0.556 cm/s2 for a frequency of 0.003 events/year (1 event every thousand years)
- 14. Case study 3: Milazzo (sicily) 0,000001 0,00001 0,0001 0,001 0,01 0,1 1 0,001 0,01 0,1 1 10 Exceedance Probability(1 y) g Hazard curve 0,00E+00 2,00E-03 4,00E-03 6,00E-03 8,00E-03 1,00E-02 1,20E-02 1,40E-02 1,60E-02 0 0,5 1 1,5 2 2,5 3 3,5 4 Probabilità PGA(cm/s^2) Probability of Damage Above Ground Steel Pipeline(WS, GF, CP) RS>=RS1 RS=rs2 There is a maximum probability at a g of 0.556c cm/s2 corresponding to a frequency of 0.014 events/year (1 event per 100 years) in RS2.
- 15. Conclusions The use of the latest generation HDPE materials resistant to hydrogen embrittlement and capable to operate at high pressures provides considerable savings in the construction and assembly of new hydrogen pipeline lines. In the design of the new lines, greater attention must be paid to the type of joints, in order to maintain a continuity of performance necessary to consider the pipeline as a CP pipeline. The seismic vulnerability of the old hydrogen pipelines types and those of the new generation were analyzed. Regards the new generation pipelines, an analysis of historical data of their performance at earthquakes is required, in order to obtain data for a more accurated evaluation. A greater amount of data is also required for the D<150 mm pipelines in order to have consistent data for the construction of fragilities in RS1. From the three locations analyzed with different assembly conditions and techniques, the best performances are recorded for the buried steel hydrogen pipelines with welded joints in the presence of SGS. It is also verified that, for surface pipelines the greatest probability of damage occurs in sicily, this in accordance with the fact that the seismic risk is higher than in places such as bavaria (germany) and maastricht (netherlands).