Table 3: Summary of pipeline reinforcement measures.

Reinforcement measuresEffect on horizontalEffect on horizontalEconomic costReinforcement effectOptimum parameters

The soil reinforcement at passive zone in the pitYoung’s modulus EsGreatGreatHighGeneralEs = 60 MPa
RS depth/RS widthGreatGeneralGeneralWhen Br = 3 m, Hr/Br = 2

The soil reinforcement underneath pipelineWeakGreatGeneralGeneralWhen Br = 3 m, Hr = 9 m

The soil reinforcement between pipeline and pitWeakGreatGeneralGeneralWhen Br = 1 m, Hr = 12 m

Bracing reinforcementPositionGreatGreatLowGreatAt the same horizontal plane of underground pipeline
Strut diameterGeneralGeneralLowGenerald = 0.6 m

Diaphragm wall reinforcementThicknessGeneralGeneralHighGeneralWall thickness is 800 mm
DepthWeakWeakHighWeakWall depth is 37.5 m