BS ISO 16134:2020 pdf download.Earthquake-resistant and subsidence- resistant design of ductile iron pipelines.
4 Earthquake-resistant design
4.1 Seismic hazards to buried pipelines
In general there are several main causes of seismic hazards to buried plpelAnes:
a) ground displacement and ground strain caused by selsmr ground shaking:
b) ground deformation such as .i ground surface crack, ground subsidence and lateral spread induced by liquefaction;
c) relative displacement at the connecting part with the structure. etc4
d) ground displacement and rupture along a fault zone.
Since the ductile iron pipe has high tensile strength as well as the capacity for espansn/contraction and deflection From its joint part. giving it the ability to follow the ground movement during the earthquake, the stress generated on the pipe body is relatively small, Few ruptures of pipe body have occurred during earthquakes in the pasL It is therefore Important to consider whether the pipeline can follow the ground displacement and ground strain without slipping out of joint when considering its earthquake resistance. The Internal hydrodynamic surge pressures induced by seismic shaking are normally small enough not to be considered,
4.2 QualItative design considerations
4.2.1 General
EXAMPLE Use of shorter pipe segments, special joints or sleeves and anti•sIipout mechanisms according to the antwlpated Intensity or mature of the earthquake
b) Lay pipelines in a firm foundation.
c) Use smooth back till materials.
NOTE Polyethylene sleeves and special coating are au..’ ir1ei live in pecial casei.
d) Install more valves
4.22 Where high earthquake resistance is needed
It is desirable to enhance the earthquake resistance ol parts connecting the pipelines to structures and when burying the pipes In
a) soft ground such as alluvium,
h) reclaimed ground.
c) tilled ground,
d) suddenly changing soil types (geology) or topography.
e) sloping griiund.
fl near revetments,
g) liquefiable ground, and/or
h) near an active fault.
4.3 Design procedure
To make earthquake-resistant design for ductile iron pipelines:
a) select the piping route;
b) investigate the potential for earthquakes and ground movement;
c assume probable earthquake motion (seismic intensity);
d)undertake earthquake resistance calculation and safety checking;
e) select joints.
Solid/firm foundations should be chosen for the pipeline route.
When investigating earthquakes and ground conditions, take into account any previous earthquakes in the area where the pipeline is to be laid. BS ISO 16134 pdf download.