PSI - Issue 60

Dhanesh N. et al. / Procedia Structural Integrity 60 (2024) 456–470 Dhanesh et al. / Structural Integrity Procedia 00 (2019) 000 – 000

458

3

considered pipeline crossing the embankment is shown in Fig.1. The slope of the embankment is 1:1. The considered pipeline is protected with an 18” steel casing pipe ( API 5L-X42), which is 72 m long and 4.78 mm thick. As per the ILI data, the dent damage is located approximately 9 m away from the casing end. The dent is located close to the edge of the road at a depth of 7.5 m below the road surface. The design code of the pipeline is ASME B 31.4 and OISD 14. The pipeline is subjected to internal pressure and external pressure due to soil weight and vehicular movement. The summary of design data of the pipeline is presented in Table 1 below. The pipeline passes through silty medium dense sand type soil (native soil). Since the embankment is constructed in layers, the modulus of elasticity of the embankment will be higher than that of native soil due to compaction.

Fig. 1. Details of the road and embankment

Table 1. Summary of design data. Item

Description

Nominal Diameter Nominal Thickness Corrosion Allowance

12”

7.1 mm 0.5 mm

Type of Pipe

ERW

MOC

API 5L X60

Design Pressure Operating Pressure

98 kg/cm 2

40-50 kg/cm 2